DRAGOJEVIĆ v. CROATIA JUDGMENT 34 B. Use of evidence obtained by secret surveillance in the proceedings 1. Admissibility 124. The Court notes that this complaint is not manifestly ill-founded within the meaning of Article 35 § 3 (a) of the Convention. It further notes that it is not inadmissible on any other grounds. It must therefore be declared admissible. 2. Merits (a) The parties’ submissions 125. The applicant contended that he had not had a fair trial because the trial bench had admitted in evidence the recordings unlawfully obtained by virtue of the secret surveillance orders and had based its decisions on that evidence. This had been contrary to the relevant rules on admissibility of evidence under the Code of Criminal Procedure which had rendered his trial unfair. 126. The Government submitted that during the proceedings the applicant had had every possibility to examine the recordings obtained by secret surveillance and to oppose their use as evidence. Indeed, he had challenged the lawfulness of such evidence and had asked that they be excluded from the case file. The domestic courts had dismissed his request and provided sufficient reasons for their decisions. (b) The Court’s assessment (i) General principles 127. The Court reiterates that its duty, according to Article 19 of the Convention, is to ensure the observance of the engagements undertaken by the Contracting States to the Convention. In particular, it is not its function to deal with errors of fact or of law allegedly committed by a national court unless and in so far as they may have infringed rights and freedoms protected by the Convention. While Article 6 guarantees the right to a fair hearing, it does not lay down any rules on the admissibility of evidence as such, which is therefore primarily a matter for regulation under national law (see, amongst many others, Schenk v. Switzerland, 12 July 1988, §§ 45-46, Series A no. 140; and Teixeira de Castro v. Portugal, 9 June 1998, § 34, Reports of Judgments and Decisions 1998-IV). 128. It is not the role of the Court to determine, as a matter of principle, whether particular types of evidence – for example, unlawfully obtained evidence – may be admissible or, indeed, whether the applicant was guilty or not. The question which must be answered is whether the proceedings as a whole, including the way in which the evidence was obtained, were fair. This involves an examination of the “unlawfulness” in question and, where