5.  The applicant was born in 1980 and lives in Slavonski Brod. 6.  In response to a request from the police, on 26 November 2007 the State Attorney’s Office for the Suppression of Corruption and Organised Crime (Ured za suzbijanje korupcije i organiziranog kriminaliteta) asked an investigating judge of the Zagreb County Court (Županijski sud u Zagrebu) to authorise the use of special investigative measures, namely tapping the telephone conversations of the applicant and several other individuals on the grounds of their suspected participation in organised drug trafficking, customs evasion, and the abuse of power and authority. 7.  On 27 November 2007 the investigating judge granted the request and issued an order for the use of secret surveillance measures. His statement of reasons read as follows:
“The State Attorney’s Office for the Suppression of Corruption and Organised Crime asked the investigating judge to authorise the use of phone tapping measures under Article 180 § 1 (1) of the Code of Criminal Procedure in respect of ... Damir Bašić [and others] on the grounds that a preliminary [police] investigation suggested that these individuals were engaged in criminal activity involving the commission of offences under Articles 173 §§ 1 and 2, 298 § 2, 337 and 333 of the Criminal Code.
Having assessed the [State Attorney’s] request, and in view of [the request from the police], it is established that there is probable cause for believing that the criminal offences have been committed and that the requisite investigation in the present case could not be carried out by any other means, or would be extremely difficult. In addition, given that the matter concerns the offences enumerated in Article 181 § 1 (2) of the Code of Criminal Procedure, the request has been granted and it was decided as indicated in the operative part of this order.” 8.  In the course of the investigation, the investigating judge issued several further secret surveillance orders to the same effect. In addition to the phone tapping, the investigating judge also authorised the covert monitoring of the suspects. 9.  On the basis of the evidence obtained by the aforementioned use of secret surveillance measures, on 2 July 2008 the police lodged a criminal complaint against the applicant and five other persons with the Slavonski Brod County State Attorney’s Office (Županijsko državno odvjetništvo u Slavonskom Brodu) in connection with suspected drug trafficking and customs evasion. 10.  On the same day the applicant was brought before an investigating judge of the Slavonski Brod County Court (Županijski sud u Slavonskom Brodu), who questioned him in connection with the charges brought against him. The applicant decided to remain silent and not give any evidence. 11.  On 4 July 2008 the investigating judge opened an investigation in respect of the applicant and the other suspects in connection with suspected drug trafficking. She also ordered the applicant’s pre-trial detention. 12.  After the completion of the investigation, on 25 November 2008 the Slavonski Brod County State Attorney’s Office indicted the applicant and four other persons in the Slavonski Brod County Court on charges of drug trafficking. 13.  On 12 June 2009 the applicant asked the Slavonski Brod County Court to exclude from the proceedings the evidence obtained by means of secret surveillance as being unlawfully obtained. He argued that the secret surveillance had been carried out on the basis of orders which had been issued contrary to the relevant domestic law and practice of the Constitutional Court (Ustavni sud Republike Hrvatske) in that they contained no reasoning justifying the use of secret surveillance. 14.  At a hearing on 18 June 2009 the Slavonski Brod County Court dismissed the applicant’s request as unfounded. At the same hearing the applicant pleaded not guilty to the charges held against him, whereas three other defendants pleaded guilty. The trial bench heard several witnesses and an expert witness and examined the reports in the case file. 15.  A further hearing was held on 29 September 2009 at which the applicant reiterated his request for the exclusion of the evidence obtained by secret surveillance as being unlawfully obtained. The applicant further contended that his exact location at the moment of the alleged commission of the offence at issue should be established by obtaining the location tracking data of the mobile phone which he had allegedly used. 16.  The trial bench dismissed the applicant’s request as unfounded and decided to continue with the examination of evidence. It heard two witnesses and an expert witness and adjourned the proceedings in order for the defence to obtain copies of the secret surveillance recordings. 17.  At a hearing on 26 November 2009 the applicant argued that a list of incoming and outgoing calls for the mobile phones allegedly used by the defendants should be obtained in order to clarify all the circumstances of the case. The trial bench dismissed his request as unfounded and proceeded with the examination of the secret surveillance audio recordings. The defence did not have particular objections to the recordings but they expressed doubts as to the identification of one of the speakers as one of the applicant’s co-accused. 18.  At a hearing on 14 December 2009 the trial bench heard further secret surveillance audio recordings. The defence had no particular objections to the recordings but requested that some additional evidence and recordings be examined at the trial. 19.  Further hearings were held on 2 and 19 February 2010 at which the trial bench examined the secret surveillance recordings. The applicant reiterated his request for an expert telecommunications report to establish the location of his mobile phone at the moment of the alleged offence. The defence also challenged the credibility of a police report concerning the applicant’s surveillance, expressing doubts as to the reasons why there were no recordings accompanying that report. In this connection the trial bench heard evidence from the police officer in charge of the operation, Z.H., who explained that no recordings had been made for fear that, in the circumstances, the suspects might have noticed that they were being followed. The trial bench also heard evidence from another police officer, B.V., who explained the method of identifying the mobile phones used by the defendants. Following B.V.’s questioning, the trial bench dismissed all further requests for the examination of evidence and adjourned the hearing for the preparation of the defendants’ closing statements. 20.  On 26 February 2010 the trial bench heard the parties’ closing arguments. 21.  By a judgment of 1 March 2010 the Slavonski Brod County Court found the applicant guilty as charged and sentenced him to five years’ imprisonment. As to the applicant’s arguments concerning the alleged unlawfulness of the secret surveillance orders, that court held that the orders had outlined reasons for believing that the applicant had probably participated in the commission of the offence at issue and that the investigation could not have been conducted by other means. 22.  The Slavonski Brod County Court further held that all doubts on the part of the defence as to the accuracy of the recordings had been clarified by questioning the police officers, who had explained the manner in which the recordings had been obtained and documented. It also found that the available police reports on covert monitoring provided sufficient information as to the defendant’s location at the moment of the commission of the offence and that there was therefore no need to obtain further evidence, such as mobile phone location data, in that respect. It therefore dismissed the applicant’s objections to the use of the evidence obtained by secret surveillance and proceeded with its detailed assessment when determining the applicant’s guilt. 23.  On 21 April and 6 July 2010, relying on the case-law of the Constitutional Court ‒ according to which secret surveillance orders needed to be properly reasoned in order to satisfy the requirement of lawfulness under the relevant domestic law ‒ the applicant lodged an appeal against the first-instance judgment with the Supreme Court (Vrhovni sud Republike Hrvatske). He also complained about the use of the evidence thereby obtained in securing his conviction. 24.  On 21 September 2010 the Supreme Court dismissed the applicant’s appeal and upheld the first-instance judgment. It stressed in particular that the alleged lack of reasoning justifying the secret surveillance orders could not result in the unlawfulness of the evidence obtained by the use of such secret surveillance. It also held that all the relevant circumstances of the case had been properly established by the first-instance court and that the applicant’s conviction had been based on a proper and convincing assessment of evidence and the relevant facts. 25.  On 23 November 2010 the applicant lodged a constitutional complaint with the Constitutional Court complaining that his right to respect for private life and confidentiality of correspondence, as guaranteed under Articles 35 and 36 § 1 of the Constitution, had been breached by the unlawful and unjustified secret surveillance, and that his right to a fair trial under Article 29 of the Constitution had been breached by the use of the evidence thereby obtained in the criminal proceedings against him. 26.  On 11 July 2012 the Constitutional Court dismissed the applicant’s constitutional complaint as unfounded, endorsing the reasoning of the Supreme Court. It considered in particular that the criminal proceedings against the applicant, taken as a whole, had not been unfair. The decision of the Constitutional Court was served on the applicant on 11 September 2012.