1.

By this request for a preliminary ruling, the Spetsializiran nakazatelen sad (Specialised Criminal Court, Bulgaria) seeks to ascertain whether a practice whereby authorisations to use covert surveillance measures in order to intercept, record and store telephone conversations between suspects (‘telephone tapping’) in the form of a generic template text that does not contain individualised reasons is compatible with Article 15(1) of Directive 2002/58/EC, ( 2 ) read in conjunction with Article 5(1) and recital 11 thereof. It also wishes to ascertain whether the lack of an individualised statement of reasons in such authorisations can be remedied by a retrospective, de novo, assessment by the trial judge and, if not, whether evidence found to have been obtained in breach of those provisions may be admitted as evidence.

2.

Recital 2 of Directive 2002/58 states:

‘This Directive seeks to respect the fundamental rights and observes the principles recognised in particular by the Charter of Fundamental Rights of the European Union [(“the Charter”)]. In particular, this Directive seeks to ensure full respect for the rights set out in Articles 7 and 8 of that Charter.’

3.

Recital 11 of Directive 2002/58 states:

‘Like Directive 95/46/EC ( 3 ), this Directive does not address issues of protection of fundamental rights and freedoms related to activities which are not governed by Community law. Therefore it does not alter the existing balance between the individual’s right to privacy and the possibility for Member States to take the measures referred to in Article 15(1) of this Directive, necessary for the protection of public security, defence, State security (including the economic well-being of the State when the activities relate to State security matters) and the enforcement of criminal law. Consequently, this Directive does not affect the ability of Member States to carry out lawful interception of electronic communications, or take other measures, if necessary for any of these purposes and in accordance with the European Convention for the Protection of Human Rights and Fundamental Freedoms [(“ECHR”)], as interpreted by the rulings of the European Court of Human Rights [(“ECtHR”)]. Such measures must be appropriate, strictly proportionate to the intended purpose and necessary within a democratic society and should be subject to adequate safeguards in accordance with the [ECHR].’

4.

Under the heading ‘Confidentiality of the communications’, Article 5 of Directive 2002/58 provides in paragraph 1 thereof:

‘Member States shall ensure the confidentiality of communications and the related traffic data by means of a public communications network and publicly available electronic communications services, through national legislation. In particular, they shall prohibit listening, tapping, storage or other kinds of interception or surveillance of communications and the related traffic data by persons other than users, without the consent of the users concerned, except when legally authorised to do so in accordance with Article 15(1). This paragraph shall not prevent technical storage which is necessary for the conveyance of a communication without prejudice to the principle of confidentiality.’

5.

Article 15, headed ‘Application of certain provisions of Directive 95/46/EC’, states in paragraph 1 thereof:

‘Member States may adopt legislative measures to restrict the scope of the rights and obligations provided for in Article 5, Article 6, Article 8(1), (2), (3) and (4), and Article 9 of this Directive when such restriction constitutes a necessary, appropriate and proportionate measure within a democratic society to safeguard national security (i.e. State security), defence, public security, and the prevention, investigation, detection and prosecution of criminal offences or of unauthorised use of the electronic communication system, as referred to in Article 13(1) of Directive 95/46/EC. To this end, Member States may, inter alia, adopt legislative measures providing for the retention of data for a limited period justified on the grounds laid down in this paragraph. All the measures referred to in this paragraph shall be in accordance with the general principles of Community law, including those referred to in Article 6(1) and (2) of the Treaty on European Union.’

6.

Article 121(4) of the Bulgarian Constitution provides that ‘judicial acts shall state reasons’.

7.

Article 34 of the Nakazatelno-protsesualen kodeks (Code of Criminal Procedure; ‘the NPK’) ( 4 ) provides that ‘every act of the court must contain … a statement of reasons …’

8.

Article 172 of the NPK is in the following terms:

‘(1)   The authorities responsible for the pre-trial stage of the proceedings may make use of special investigative methods – electronic and technical equipment …, which shall serve to document the activities of the monitored persons …

(2)   Special investigative methods shall be used where that is necessary for the investigation of serious intentional criminal offences …, where the establishment of the circumstances in question is impossible in any other way, or is accompanied by exceptional difficulties.’

9.

Under Article 173(1) of the NPK:

‘In order to make use of special investigative methods in the pre‑trial stage of the proceedings, the supervising public prosecutor shall submit to the court a written request stating reasons. …’

10.

Article 174 of the NPK provides:

‘…

(3)   An authorisation for the use of special investigative methods in proceedings within the jurisdiction of the Spetsializiran nakazatelen sad [(Specialised Criminal Court)] shall be granted in advance by its President …

(4)   The authority referred to in paragraphs 2 to 3 shall rule by reasoned order …’

11.

Article 3(1) of the Zakon za spetsialnite razuznavatelni sredstva (Law on Special Investigative Methods; ‘the ZSRS’) ( 5 ) provides:

‘Special investigative methods shall be used where that is necessary to prevent and detect serious intentional criminal offences …, where the collection of the necessary information is impossible in any other way, or is accompanied by exceptional difficulties.’

12.

Article 12(1)(1) of the ZSRS provides:

‘Special investigative methods shall be used for persons in respect of whom there is information and reasonable grounds to believe that they are preparing, committing or have committed any of the serious intentional criminal offences referred to in Article 3(1).’

13.

Article 13(1) of the ZSRS specifies the authorities and agencies that may apply to employ special investigative methods and to make use of the information and material evidence gathered by means of those methods.

14.

Article 14(1)(7) of the ZSRS states:

‘The use of special investigative methods shall require a reasoned written request from the relevant administrative head of the authorities referred to in Article 13(1) or the supervising public prosecutor, or, as the case may be, from the authority referred to in Article 13(3), and in the case of the directorate referred to in Article 13(1)(7), from its director, containing … the reasons why the collection of the necessary information is impossible in any other way, or a description of the exceptional difficulties accompanying its collection.’

15.

Article 15(1) of the ZSRS provides:

‘The heads of the authorities referred to in Article 13(1) or the supervising public prosecutor, and in the case of the directorate referred to in Article 13(1)(7), the President of the Commission for the combating of corruption and for the confiscation of illegally obtained assets, shall submit the request to the Presidents of the Sofiyski gradski sad [(Sofia city court, Bulgaria)], the relevant regional or military courts, the Spetsializiran nakazatelen sad [Specialised Criminal Court], or to a Vice-President authorised by them, who shall, within 48 hours, authorise in writing the use of special investigative methods or refuse their use, stating the reasons for their decisions.’

16.

The Spetsializirana prokuratura (Specialised public prosecutor’s office, Bulgaria) brought criminal proceedings against five persons for their alleged participation in an organised criminal group that assisted third-country nationals in entering Bulgarian territory illegally; the same individuals were also accused of giving or taking bribes in connection therewith. Those acts constitute ‘serious offences’ under Bulgarian law.

17.

On 10 April 2017, during the pre-trial stage of the proceedings, the prosecutor filed an application to use special investigative methods, including telephone tapping, in respect of one of the accused persons, IP.

18.

The application is over eight pages in length. The first page and the footer on pages 2 to 8 bear a reference number. The application begins with a description of the intended operational measures. It identifies the intended subject of the measures by name, identification number, address, function and place of work. It states the mobile telephone number and other details of the prepaid card used by the person to be placed under surveillance.

19.

The application contains grounds justifying recourse to the surveillance measures. The first paragraph under that heading identifies the pre-trial proceedings and the criminal offence under investigation, both by reference to the relevant articles of the NPK and the nature of the offence. The second paragraph refers to witness testimony obtained by the Spetsializirana prokuratura (Specialised public prosecutor’s office) about the criminal activity, its structure and the participants’ role in it. The third paragraph contains further witness testimony which details how the criminal group operated and the subject’s involvement. That paragraph also includes a description of the way in which the subject communicated with others in the criminal group, together with a reference to the mobile telephone number used which matches that listed in the first paragraph of the application. That section concludes with the observation that the witness testimony justifies the conclusion that a criminal group is operating in Bulgaria.

20.

The application explains why the requested measures are considered necessary and sets out the actions that had already been taken in order to identify the persons involved in the criminal group. There is a further detailed explanation as to why the activities of the subject infringe various provisions of national and EU law.

21.

The next paragraph of the application sets out the reasons why evidence leading to conviction cannot be obtained in any other way. It asserts in particular that the persons involved form a closed group and that it is difficult to obtain evidence relating to their meetings. The final paragraph of the application gives details of the authorised official who is to be notified of the results of the proposed surveillance.

22.

On the same day, the President of the Spetsializiran nakazatelen sad (Specialised Criminal Court) authorised the interception of telephone conversations, the recording thereof and the storage of the recordings for the purposes of criminal proceedings. The order records the name and function of the person who authorised the measures. It states that the authority making the application acted within its competence and that there are sufficient indications that an offence under Article 172(2) of the NPK or Article 3(1) of the ZSRS, which falls within the jurisdiction of the Spetsializiran nakazatelen sad (Specialised Criminal Court), has been committed. It states that the requirements of Articles 4, 12 and 21 of the ZSRS, or Article 175(2) of the NPK, have been complied with. It authorises the surveillance methods listed with regard to the person identified in the application bearing a reference number corresponding to that which appears on the first page and in the footer of pages 2 to 8 of the application. The authorisation is signed, sealed and dated 10 April 2017. The first page of the request for authorisation bears the same signature, seal and date.

23.

Similar applications were made in respect of other persons under investigation in connection with their involvement in the same criminal group. The statements of reasons given by the President of the Spetsializiran nakazatelen sad (Specialised Criminal Court) appear to be identical, save that in each case the authorisation appears to cross-refer to a different application.

24.

According to the referring court, the generic template text of the authorisations covers the various scenarios in which covert surveillance may lawfully be authorised. It is standard practice that the authorisation does not include an individualised statement of the reasons for its issue. The referring court therefore had doubts as to whether the authorisations were properly reasoned.

25.

As a result of the authorised surveillance measures, certain of the suspects’ telephone conversations were recorded and stored. The referring court accepts that those conversations are relevant to prove the criminal charges against the accused, but queries whether they are admissible if the authorisations are deemed to be unlawful. It therefore stayed the proceedings and referred the following questions to the Court of Justice for a preliminary ruling:

26.

IP, DD, the Czech Republic, Ireland and the European Commission filed written observations. At the hearing on 6 July 2022, Ireland and the Commission presented oral argument and replied to questions from the Court.

27.

As regards the first question, IP and DD consider that the authorisations are unlawful because they do not contain an individualised statement of reasons. As a result, their right to privacy was inadequately protected from arbitrary interference. They also claim that they are unable to challenge the authorisations effectively, which infringes their rights under Article 47 of the Charter. The Czech Republic, Ireland and the Commission are of the view that reading the application and the authorisation side by side may be sufficient to allow the accused persons to mount an effective legal challenge against the authorisations with a view to excluding evidence obtained on foot thereof.

28.

As regards the second question, IP and DD consider that the unlawfully obtained evidence is inadmissible. DD also takes the view that it is not possible for the trial judge to assess the lawfulness of the authorisations retrospectively. Ireland considers that the admissibility of evidence is a procedural matter not regulated by EU law that falls within the exclusive competence of the Member States. The Commission agrees with Ireland, subject to the proviso that, according to this Court’s case-law, evidence which pertains to a technical field of which judges have no knowledge and which is likely to have a preponderant influence on the assessment of the facts must be excluded in all circumstances.

29.

The referring court wishes to ascertain whether a judicial authorisation for telephone tapping in the form of a generic template text which states that the statutory provisions for surveillance have been complied with, but does not contain individualised reasons, is compatible with Article 15(1) of Directive 2002/58, read in conjunction with Article 5(1) and recital 11 thereof.

30.

Under Article 1(3) of Directive 2002/58, as interpreted by this Court’s case-law, all operations processing personal data carried out by providers of electronic communications services fall within the scope of that directive, including processing operations that result from obligations public authorities impose on those providers. It is only where Member States directly implement measures that derogate from the rule that electronic communications are confidential, without imposing obligations on providers of electronic communications services, that the protection of data is not covered by Directive 2002/58 but by national law, subject to the application of Directive (EU) 2016/680, ( 6 ) with the result that those national measures must comply with, inter alia, national constitutional law and the ECHR. ( 7 )

31.

The order for reference does not disclose, and the parties that attended the hearing were unable to confirm, whether the surveillance measures at issue here were implemented by electronic communications service providers. The identity of the body that carried out the surveillance measures is a matter for the national court to establish.

32.

For the purpose of replying to the questions, I will assume that they were carried out by electronic communications service providers and that the measures therefore come within the scope of Directive 2002/58. ( 8 )

33.

A second issue arises from the fact that Article 15(1) of Directive 2002/58 permits Member States to ‘adopt legislative measures that restrict the scope of the rights and obligations provided for in Article 5 …’. The referring court’s doubts are not so much about the national legislative measures that transpose Article 15(1), but rather about how the judiciary gives effect to them. Do those doubts place the first question beyond the scope of Article 15(1) of Directive 2002/58? I do not think that they do. The national legislation provides that authorisations must be in the form of a reasoned order. The material before this Court indicates that the authorisations include a statement to the effect that the requirements of the law are met. The question is whether that reasoning is sufficient, given that the orders are in the form of a template text that does not contain individualised reasons. The referring court’s doubts thus relate to the interpretation of EU law in the light of the applicable national rules and judicial practice.

34.

Article 5(1) and Article 15(1) of Directive 2002/58, read together, require Member States essentially to prohibit listening, tapping, storage or other kinds of interception or surveillance of communications to which the users concerned do not consent, unless that is necessary, appropriate and proportionate to prevent, investigate, detect and prosecute criminal offences. Such measures must be in accordance with the general principles of EU law, including the principle of proportionality and those to which Article 6(1) and (2) TEU refers.

35.

Pursuant to Article 6(1) TEU, the Union recognises the rights, freedoms and principles set out in the Charter. According to Article 51(1) of the Charter, its provisions are addressed to the Member States when they are implementing EU law.

36.

Authorisations for telephone tapping constitute an interference with the rights of the accused persons guaranteed by Article 7 of the Charter. ( 9 ) Such interference may be allowed, in accordance with Article 52(1) of the Charter, only if it is provided for by law and if, while respecting the essence of those rights and subject to the principle of proportionality, it is necessary and genuinely meets objectives of general interest that the Union recognises.

37.

The principle of effectiveness is a general principle of EU law whereby the application of EU law must not be rendered impossible or excessively difficult. ( 10 ) It comprises the right to an effective judicial review. ( 11 ) The first paragraph of Article 47 of the Charter, moreover, provides that everyone whose rights and freedoms guaranteed by EU law are violated has the right to an effective remedy before a tribunal in compliance with the conditions laid down in that article. Where the grant of the authorisation did not involve hearing the subject of the surveillance measures, as in the present circumstances, it is the first paragraph of Article 47 of the Charter, relating to effective judicial review, that is relevant, and not the second paragraph on the right to a fair trial.

38.

It is settled case-law that if the right to an effective judicial review guaranteed by Article 47 of the Charter is to be effective, the person concerned must be able to ascertain the reasons for a decision taken in relation to him or her, either by reading that decision or by requesting and receiving notification of those reasons, so as to make it possible to defend his or her rights in the best possible conditions and to decide, in full knowledge of the relevant facts, whether to apply for judicial review to a court with jurisdiction to review the lawfulness of that decision. ( 12 )

39.

The extent of the obligation to state reasons may vary according to the nature of the decision challenged. That obligation falls to be examined in the light of the proceedings as a whole and all of the relevant circumstances in order to ascertain whether those concerned can bring an appropriate and effective appeal against that decision. ( 13 )

40.

In the present case, the authorisations consist of a generic template text in which only certain elements, such as reference numbers, dates and the subject, scope and duration of the surveillance measures, are individualised. It is therefore not possible for accused persons to ascertain, by reference to that document, why the judge who granted the authorisation considered that the legal requirements permitting telephone tapping had been met. Those individuals are therefore unable to defend their rights in the best possible conditions and to decide, in full knowledge of the relevant facts, whether there is any point in applying to a court with jurisdiction to review the lawfulness of these authorisations with the ultimate aim of having that evidence ruled inadmissible.

41.

The right to an effective judicial review does not, however, necessarily require the judge who granted the authorisation to set out, in his or her own words in that document, why he or she considered that the conditions to grant the authorisation were met. It is sufficient that the reasons for granting that authorisation can be reliably ascertained. If the application for an authorisation contains a clear explanation as to why the requesting authority or officer considered that the surveillance measures should be authorised, it may be assumed that the reasons stated in the application are those that persuaded the judge to grant it. ( 14 ) That is all the more so because, in this type of procedure, the application and any supporting documentation are the sole basis upon which the authorisation may be granted or refused.

42.

Points 18 to 22 of the present Opinion state that the reference numbers and ID numbers that appear on the face of the authorisations indicate that each authorisation pertains to an individual application in respect of a specific person and telephone number. The applications are structured and detailed. The legal tests that the judge must apply to grant an authorisation are relatively straightforward. Provided that an accused person is able to obtain a copy of the application that led to the grant of the authorisation in due time, ( 15 ) he or she is likely to be in a position to ascertain the reasons why the authorisation was granted and to decide, on an informed basis, whether to challenge it. It is then up to the national court to determine, on a case-by-case basis and taking into account all of the relevant circumstances, whether the right to an effective remedy that accused persons enjoy under the first paragraph of Article 47 of the Charter has been safeguarded.

43.

Article 52(3) of the Charter seeks to ensure consistency between the rights contained in that document and the corresponding rights guaranteed under the ECHR, without adversely affecting the autonomy of EU law. It is in that context that there was a discussion at the hearing as to whether the approach described in the previous point of this Opinion conflicts with the recent ECtHR judgment in Ekimdzhiev, ( 16 ) where that court assessed legal safeguards against arbitrariness and abuse with respect to covert surveillance, retention of and access to communications data in the context of the practice of the Spetsializiran nakazatelen sad (Specialised Criminal Court) in the years from 2015 to 2019.

44.

The ECtHR found that the vast majority of surveillance authorisations issued did not contain a proper statement of reasons. It nevertheless observed that the lack of reasoning alone did not automatically lead to the conclusion that judges had not properly reviewed applications for surveillance authorisations, although a number of factors caused it to have serious misgivings in that respect. ( 17 )

45.

For present purposes it suffices to observe that the judgment of the ECtHR in Ekimdzhiev, while raising significant concerns about aspects of the judicial authorisation of covert surveillance in Bulgaria, left open the possibility that such surveillance was authorised in circumstances where the judge authorising it properly considered that it was genuinely necessary, appropriate and proportionate. In any event, an accused person who is subject to surveillance carried out on foot of an authorisation must be in a position to ascertain the reasons why that authorisation was granted and to decide, on an informed basis, whether to challenge it. It is for the national court to assess, in any given case, whether such a challenge is well founded.

46.

I therefore propose that the Court answer the first question as follows:

Article 47 of the Charter and Article 15(1) of Directive 2002/58, read in conjunction with Article 5(1) and recital 11 thereof, do not preclude a practice whereby the interception, recording and storage of telephone conversations of suspects is authorised by means of a generic template text in which it is asserted that the statutory provisions have been complied with but which does not contain individualised reasons in that respect, provided that the reasons for the authorisation can be reliably ascertained and effectively challenged by the accused person who was the subject of the surveillance by reading the authorisation and the application for that authorisation side by side.

47.

Since the assessment of the lawfulness of the authorisation is a matter for the referring court, the second question requires an answer.

48.

The second question is based upon two assumptions. The first is that incriminating evidence was obtained by covert surveillance carried out on foot of an authorisation that was unlawful because it was improperly reasoned. The second is that the accused person who was subject to that surveillance cannot effectively challenge the legal basis upon which it was authorised.

49.

The order for reference inquires whether the trial judge may remedy an illegality in the authorisation due to a lack of proper reasoning. Although the mechanics and consequences of such a retrospective assessment are not entirely clear, and there are doubts as to whether the trial judge has jurisdiction to rectify such an illegality, in order to provide a useful response to the referring court it appears appropriate to consider that issue.

50.

The Commission observed that the second question requires consideration of how any unlawfully obtained evidence might impact on the overall fairness of the criminal trial. The order for reference does not address that issue. Nor does the referring court provide information about the applicable national procedural rules, notably how such evidence would be treated in the proceedings before it. The issue the Commission raises thus appears to be entirely hypothetical, for which reason the Court ought not to address it in the context of this reference.

51.

The Court’s case-law on the general retention of data and access thereto provides an answer to that question. National law must determine the conditions under which electronic communications service providers must grant the competent national authorities access to data. It must contain clear and precise rules to govern the scope and application of measures adopted for that purpose and impose minimum safeguards, so that persons whose personal data are affected have sufficient guarantees that such data will be effectively protected against the risk of abuse. Interference must be limited to what is strictly necessary. For the purposes of fighting crime, access can be granted only to the data of individuals suspected of planning, committing or having committed a serious crime or of being implicated in one way or another in such a crime. To ensure that those conditions are fully observed, it is essential that such access is subject to a prior review, by a court or by an independent administrative body, of a reasoned request submitted by the appropriate authorities within the framework of national procedures for the prevention, detection or prosecution of crime. That assessment must always be prospective, except in cases of duly justified urgency where it must be conducted within a short period of time thereafter. ( 18 ) Were it otherwise, by the time a retrospective assessment of the lawfulness of the surveillance measures had been conducted, serious interference with the rights of the accused and of those collaterally affected would occurred. The lack of an assessment by an independent authority thus cannot be remedied by conducting a de novo assessment retrospectively.

52.

It follows that only a prior assessment can ensure that obligations are not imposed unnecessarily on electronic communications service providers, that the interference with the fundamental rights enshrined in the Charter is not arbitrary and that the conditions set out in Article 15(1) of Directive 2002/58 are met. That is consonant with the approach adopted by the ECtHR in its judgment in Dragojević, ( 19 ) where it did not accept a practice whereby the Croatian courts assessed retrospectively whether surveillance orders had been lawful at the time they had been issued.

53.

Article 6 ECHR guarantees the right to a fair trial but does not lay down any rules on the admissibility of evidence as such, which is primarily a matter for national law. Nor does the ECtHR consider that its role is to determine the admissibility of unlawfully obtained evidence. ( 20 )

54.

It is settled case-law that, in the absence of EU rules on the matter, it is for the domestic legal system of each Member State to lay down the detailed procedural rules that govern actions intended to safeguard rights which individuals derive directly from EU law, provided that such rules are not less favourable than those governing similar domestic actions (the principle of equivalence) and that they do not render practically impossible or excessively difficult the exercise of those rights (the principle of effectiveness). ( 21 ) Such rules must also respect fundamental rights, the principle of legality and the rule of law, which features are among the European Union’s founding values. ( 22 )

55.

Under the principle of equivalence, it is for the national court hearing criminal proceedings based on information or evidence obtained in contravention of the requirements stemming from Directive 2002/58, to determine whether national law or practice lays down less favourable rules on the admissibility and use of that material than those governing the admissibility and use of information and evidence obtained in breach of domestic law.

56.

As for the principle of effectiveness, the objective of national rules on the admissibility and use of information and evidence is, in accordance with the choices made by those rules, to prevent information and evidence that has been obtained unlawfully from unduly prejudicing the trial of a person suspected of having committed criminal offences. That objective may be achieved under national law not only by prohibiting the use of such information and evidence at trial, but also by national rules and practices that govern the assessment of, and the weight to be given to, such material or by factoring in whether that material had been obtained unlawfully when imposing sentence. ( 23 ) The principle of effectiveness has nevertheless led the Court to fashion a rule that requires the mandatory exclusion of evidence in certain defined circumstances. Where a party is not in a position to comment effectively on evidence which pertains to a technical field of which the judges hearing the case have no knowledge and which is likely to have a preponderant influence on the assessment of the facts, that evidence must be excluded. ( 24 )

57.

By its second question, the referring court appears to query that approach. It is therefore useful to examine the relevant case-law.

58.

In Mantovanelli the contested evidence consisted of an expert medical report, based on laboratory analyses, the expert’s interviews with witnesses and certain documents. Mr and Mrs Mantovanelli had neither been permitted to attend the interviews, nor to have sight of the documents, but they were allowed to challenge the report once it had been submitted to the court. The ECtHR was not convinced that that procedure afforded Mr and Mrs Mantovanelli a real opportunity to comment effectively on the expert report. The question the expert was instructed to answer was precisely that which the court had to determine, namely whether the facts disclosed negligence by a hospital’s medical staff through the administration of a particular pharmaceutical product to a patient. The evidence thus pertained to a technical field that was beyond the judges’ knowledge. Although the court was not bound in law by the expert’s findings, those findings were likely to have a preponderant influence on its assessment of the facts. In the light of the courts’ refusal of Mr and Mrs Mantovanelli’s application to submit a fresh expert report both at first instance and on appeal, they could have expressed their views effectively before the expert report had been lodged only by participating in the interviews with medical staff and by commenting on the relevant documents. The ECtHR thus found that, on the whole, the court proceedings were unfair. ( 25 )

59.

In Steffensen, samples of a food product had been taken for analysis in a laboratory. The result of that analysis formed the basis for the administrative authorities’ decision that the product did not meet the requisite legal standard. Under the relevant directive, the manufacturer should have had an opportunity to obtain a second opinion in order to contest that first analysis. The manufacturer had not been notified that samples had been taken and had therefore been unable to take samples from the same product. The Court, citing Mantovanelli, observed that the ECtHR’s review of the fairness of a hearing under Article 6(1) ECHR relates to the proceedings considered as a whole, including the way in which evidence was taken. It held that it was for the national court to examine whether the evidence at issue in those proceedings pertained to a technical field of which the judges had no knowledge and which was likely to have had a preponderant influence on their assessment of the facts. If those two elements were established, the national court had to inquire as to whether Mr Steffensen had a real opportunity to comment effectively on that evidence. If not, the national court was required to exclude the evidence in order not to infringe the adversarial principle and the right to a fair hearing. ( 26 )

60.

The opportunity for the defence to comment effectively on evidence is part of the adversarial principle, which is a key aspect of the right to a fair hearing protected by the second paragraph of Article 47 of the Charter ( 27 ) and Article 6(1) ECHR. ( 28 ) In Mantovanelli and Steffensen, both courts were concerned with avoiding situations where cases were decided on the basis of evidence pertaining to a technical field outside of the judges’ knowledge, which the defence was not in a position to contest. Such a procedure would confer an unfair advantage upon the party relying on that evidence, thereby infringing the opposing party’s right to a fair hearing.

61.

The evidence at issue in the proceedings before the referring court is different from that considered in Mantovanelli and Steffensen. It consists of recordings of telephone conversations of the accused persons relating to the activities under investigation. Even if that evidence is likely to have a preponderant influence on the judges’ assessment of the facts, it is difficult to see how it might pertain to a technical field of which they have no knowledge. In any event, the facts of Mantovanelli and Steffensen are but useful examples of the application of principles that national courts may take into account when ruling in criminal proceedings.

62.

It is also noteworthy that, in the interests of the administration of justice, the appropriate approach in Mantovanelli would have been to have given Mr and Mrs Mantovanelli an opportunity to participate in the process that led to the compiling of the expert’s report or to grant them permission to file the expert report that they had themselves commissioned. Similarly, the appropriate solution for persons in Mr Steffensen’s situation would have been to give them an opportunity to adduce a second opinion. The exclusion of evidence became relevant only because other, more appropriate, procedural mechanisms had ‑ erroneously ‑ been unavailable. It is a matter for the national court to assess whether such opportunities may be available to the accused persons at their trial.

63.

In the light of the foregoing, I propose that the Court give the following answer to the second question:

Article 47 of the Charter and Article 15(1) of Directive 2002/58, read in conjunction with Article 5(1) and recital 11 thereof, are to be interpreted as meaning that a national court:

64.

I therefore propose that the Court answer the questions asked by the Spetsializiran nakazatelen sad (Specialised Criminal Court, Bulgaria) as follows.