5.  On 5 and 20 March 2007 the Zagreb County State Attorney’s Office (Županijsko državno odvjetništvo u Zagrebu) asked an investigating judge of the Zagreb County Court (Županijski sud u Zagrebu) to authorise the use of secret surveillance measures in respect of M.M., on the grounds that he was suspected of drug trafficking. 6.  During the investigation and while secret surveillance measures were being used against M.M., the authorities intercepted and recorded a number of telephone conversations in connection with drug trafficking. The fourth applicant’s telephone number was noted in that respect. 7.  Following an application lodged on 3 May 2007 by the Zagreb County State Attorney’s Office, on 4 May 2007 the investigating judge of the Zagreb County Court authorised the use of secret surveillance measures in respect of the fourth applicant and three other persons, on the grounds that they were suspected of drug trafficking proscribed by Article 173 §§ 1 and 2 of the Criminal Code. Her statement of reasons reads as follows:
“On 3 May 2007 the Zagreb County State Attorney’s Office lodged an application for an order for [secret surveillance] measures under Article 180 § 1 (1) of the Code of Criminal Procedure in respect of A.J., [the fourth applicant], G.P. and N.M., due to [there being] probable cause to believe that the criminal offence proscribed by Article 173 §§ 1 and 2 of the Criminal Code had been committed.
The application of the Zagreb County State Attorney’s Office is well founded.
The application refers to the police report ... of 3 May 2007 concerning the use of secret surveillance measures in respect of M.M., alleging that there is probable cause to believe that the persons mentioned [in that report] often communicate about purchasing cocaine, [something] which is established on the basis of telephone conversations with M.M., [a person] in respect of whom this court ordered [secret surveillance] measures under Article 180 § 1 (1) and (3) of the Code of Criminal Procedure on 5 March 2007.
The investigating judge considers that the application is well founded, because in this particular case the investigation of these criminal offences could not be carried out by other means, as [the offences] concern the criminal offence proscribed by Article 173 §§ 1 and 2 of the Criminal Code.
Bearing in mind the above facts, the investigating judge [issues] an order under Article 180 § 1 (1) of the Code of Criminal Procedure ... because the stated circumstances point to there being sufficient grounds for suspecting the commission of the criminal offence proscribed under Article 173 §§ 1 and 2 of the Criminal Code.” 8.  On 1 June 2007 the Zagreb County Court issued another order, accepting an application by the Office for the Suppression of Corruption and Organised Crime (Ured za suzbijanje korupcije i organiziranog kriminaliteta, hereinafter “the OSCOC”) for the use of secret surveillance measures for a period of three months in respect of the first and fourth applicants and four other persons, on the grounds that they were suspected of drug trafficking proscribed by Article 173 § 3 of the Criminal Code. The judge’s relevant statement of reasons reads as follows:
“In explaining its application for an order implementing measures referred to in Article 180 § 1 (1) [in respect of the first applicant] and (3) of the Code of Criminal Procedure [in respect of the first and fourth applicants], the OSCOC refers to the report of the Zagreb Police Department ... of 31 May 2007. Namely, by analysing the implementation of surveillance measures and the recording of telephone conversations, that is remote communication by mobile telephones ... used by A.J. and the number ... used by [the fourth applicant], it was established on several occasions that conversations between the persons concerned and other persons were being held regarding the sale of cocaine, that is that the persons concerned, together with several other persons, continuously, as an organised group, were selling the drug cocaine on the Zagreb narcotics market. In addition to the [information stated] above, it appears that A.J. has three places where he stores drugs ... where there is cocaine, and that G.T., K.K. and [the first applicant] are the persons in charge of [those places], and A.J. is obviously not satisfied with cocaine leaving those places in an uncontrolled manner.
...
The enclosed document delivered with the OSCOC’s application ... of 31 May 2007 and the conversations monitored so far indicate that A.J., with the assistance of [the fourth applicant] has organised a criminal group that sells large amounts of cocaine (several kilograms) in the territory of Zagreb and the Republic of Croatia, [a criminal group] which, in addition to [A.J and the fourth applicant] consists of [the first applicant], G.T., K.K. and T.K.. [The first applicant] was also introduced by A.J. and [the fourth applicant] to a legal business for catering facilities, and it appears that he is the third most important person in that organisation, after [the fourth applicant]. It follows that there are grounds for suspicion that the above-mentioned persons are involved in the commission of the offence proscribed by Article 173 § 3 of the Criminal Code.
...
Given the information stated above, and since there are grounds for suspicion that an offence of narcotic abuse under Article 173 § 3 of the Criminal Code has been committed and that criminal offences of this kind are still being committed, and taking into consideration that inquiries into the criminal offences could not be carried out in any other way or would be carried out with unreasonable difficulties, given how the offences are committed, the application submitted by OSCOC ought to be accepted ...” 9.  On 14 June 2007 the OSCOC requested that an order which included additional telephone numbers be issued against the first applicant and A.J. The following day the investigating judge issued a decision allowing a surveillance measure which included new telephone numbers for a period of three months, and suspended the measure regarding the first applicant’s previous telephone numbers. The investigating judge explained that the police report of 14 June 2007 attached to the OSCOC’s application indicated that the first applicant and A.J. were using new telephone numbers to organise the smuggling and selling of cocaine, and that the measure was necessary in order to identify persons who were committing the criminal offence of drug trafficking – proscribed by Article 173 § 3 of the Criminal Code – together with the first applicant and A.J. The judge further explained that owing to the specific manner in which the latter criminal offence was being committed, inquiries into that criminal offence could not be carried out in any other way, or would be carried out with unreasonable difficulties. 10.  While secret surveillance measures were being used against the first applicant, on 27, 28 and 29 June and 2 July 2007 the authorities intercepted and recorded a number of his telephone conversations with the second and third applicants – who lived in the Netherlands at the time – in connection with drug trafficking. 11.  On 2 July 2007 the OSCOC requested that the order issued against A.J. and the fourth applicant on 4 May 2007 (see paragraph 7 above) be extended for another two months, stating that the measures carried out thus far indicated that A.J. and the fourth applicant continuously communicated regarding perpetrating the criminal offence proscribed by Article 173 § 3 of the Criminal Code. On the same day the investigating judge allowed the extension, deeming the application “well founded, because in this particular case, the investigation of these criminal offences could not be carried out by other means”. 12.  On 6 July 2007 the secret surveillance measures were suspended, since the applicants and several other persons had been arrested and a criminal complaint against them had been filed. 13.  On 1 October 2007 the OSCOC indicted the applicants and several other persons in the Zagreb County Court on charges of drug trafficking under Article 173 § 3 of the Criminal Code. In particular, they were charged with associating in the territory of Croatia and the Netherlands from May to July 2007 for the purpose of continuously smuggling large amounts of cocaine from the Netherlands to Croatia, and selling those drugs in Croatian territory with a view to acquiring pecuniary gain. As to the fourth applicant, he was charged with, inter alia, selling cocaine to B.S. in May 2007 in Zagreb, after acquiring that drug from the first applicant. 14.  In the course of the proceedings before the Zagreb County Court the applicants challenged the lawfulness of the secret surveillance, alleging that it had not been ordered in accordance with the relevant domestic law and that the evidence so obtained was not relevant or accurate, as nothing suggested that they had been involved in the alleged drug trafficking. 15.  On 25 March 2008 the trial court dismissed the applicants’ complaints concerning the alleged unlawfulness of the secret surveillance orders as unfounded, and proceeded with the examination of the case. 16.  The latter decision was confirmed by the Supreme Court (Vrhovni sud Republike Hrvatske) on 14 May 2008. The relevant statement of reasons given by the Supreme Court reads as follows:
“... this second-instance court agrees with the first-instance court’s conclusion that evidence obtained by using an investigative measure ordered against a person in respect of whom there is a reasonable suspicion that he is committing, alone or jointly with others, one of the criminal offences proscribed under Article 181 of the Code of Criminal Procedure, can be used not only against [that person], but also against every other person caught participating in [that person’s] criminal activity, [when] the criminal activity of the other person amounts to the criminal offence proscribed under Article 181 of the Code of Criminal Procedure, but always on the condition that the other person has been caught acting together with the person against whom one of the measures under Article 180 § 1(1)-(6) has been lawfully issued.
...
Section 22 of the Office for the Suppression of Corruption and Organised Crime Act (Zakon o Uredu za suzbijanje korupcije i organiziranog kriminaliteta, hereinafter ‘the OSCOC Act’) provides that in proceedings concerning criminal offences under section 21 of the OSCOC Act, the Code of Criminal Procedure and other general provisions of criminal procedure shall apply, unless the OSCOC Act provides otherwise.
Section 42(1) of the OSCOC Act is an extension of section 41 of that Act. [Section41] provides that other measures provided for in that section may be ordered for criminal offences set out in that section, in addition to measures under Article 180 § 1 of the Code of Criminal Procedure. Therefore, the content of the cited provisions of the OSCOC Act, to which the appellants refer in their appeals, does not exclude the application of special measures under Article 180 § 1 of the Code of Criminal Procedure, but such measures are extended in respect of some criminal offences by the measures provided for under section 41 of the OSCOC Act.
Consequently, in its application for special measures of inquiry into criminal offences proscribed by Article 173 § 3 of the Criminal Code in the specific case against the defendants, the OSCOC proposed the application of the provisions of Article 180 § 1 of the Code of Criminal Procedure which the court had applied when issuing the order ... of 1 June 2007. Therefore, since the OSCOC has jurisdiction over proceedings regarding the criminal offence under Article 173 § 3 of the Criminal Code and proposed ordering special measures of inquiry into such an offence under Article 180 § 1of the Code of Criminal Procedure, the court accepted the application, which is why the issued order is not unlawful. Furthermore, applying Article 180 § 1 of the Code of Criminal Procedure to the order at issue, even though daily reports and documentation regarding technical recordings drafted by the members of the police authorities who were implementing the ordered measures were not delivered to the investigating judge on a daily basis – the judge did not ask for this under Article 182a of the Code of Criminal Procedure, but this was done after the special measures had been implemented – this does not render the order in question unlawful pursuant to Article 9 §§ 1 and 2 of the Code of Criminal Procedure, nor does it make the material evidence obtained from the measures unlawful, contrary to the allegations in the defendants’ appeals.
... restricting the freedom and confidentiality of correspondence ... was necessary for conducting the criminal proceedings. It was not contrary to Article 8 of the European Convention on Human Rights and Fundamental Freedoms or contrary to the criteria set by the European Court of Human Rights, because it was based on the relevant provisions of the Code of Criminal Procedure, had a legitimate aim, and was necessary, taking into account all the specific circumstances involved in establishing the perpetrators of the criminal offence.” 17.  At a hearing held on 15 December 2008 the trial court heard M.S., a witness called by the fourth applicant. M.S. stated that he had been friends with the fourth applicant, whom he had asked to watch over his son, B.S., who had been a drug addict. In May 2007 B.S. had gone to Zagreb to purchase an air-conditioning device. B.S. had subsequently told him that in Zagreb he had purchased drugs from some people. 18.  At a hearing held on 30 January 2009 the trial court heard B.S., a witness called by the fourth applicant. B.S. stated that in May 2007 he had purchased cocaine from S.H., and not from the fourth applicant, and that this fact could be confirmed by A.P. and M.D., who had been with him on that day. The fourth applicant then asked to call A.P. and M.D., who he said would testify about the circumstances in which B.S. had purchased cocaine in May 2007. The trial court dismissed that proposal. 19.  On 4 February 2009 the Zagreb County Court found the applicants guilty as charged and sentenced the first applicant to ten years’ imprisonment, the second and the third applicants to six years’ imprisonment, and the fourth applicant to seven years’ imprisonment. In convicting them, the Zagreb County Court relied on the recordings obtained by secret surveillance, finding them lawful and credible. As to the fourth applicant, it explained that it had refused to hear A.P. and M.D. as witnesses since at that point it had already been established beyond doubt, on the basis of the results of the secret surveillance measures and the cocaine found on B.S., that B.S. had purchased the cocaine from the fourth applicant. 20.  The applicants challenged the Zagreb County Court’s judgment by lodging appeals with the Supreme Court. They contended that the secret surveillance orders had lacked the relevant reasoning as to the lawfulness and necessity of such surveillance. Moreover, they contended that the procedure for supervising the execution of the secret surveillance orders, which in the case at hand had been based on the Code of Criminal Procedure, should have been based on special legislation concerning organised crime (the OSCOC Act). The OSCOC Act required the police to submit daily reports to the investigating judge concerning the execution of such orders, something which had not been done in their case. The applicants further challenged the findings which were based on the recordings obtained by secret surveillance. The second and third applicants also contended that the secret surveillance orders had not been issued in respect of them, and that the secret surveillance had been conducted outside Croatian territory in the absence of a request for international legal assistance in criminal matters. In their view, there was no provision for this in the relevant domestic law, and thus the secret surveillance carried out in respect of them had run counter to Article 36 of the Constitution and Article 8 of the Convention. The fourth applicant also complained that the trial court had failed to call two defence witnesses he had asked to be called (A.P. and M.D.), who would have confirmed B.S.’ statement that he had not purchased cocaine from the fourth applicant, but from S.H. Lastly, the first applicant, who disputed his conviction and sentence, challenging all factual aspects of the case and alleging procedural errors in the trial, asked that his lawyer be allowed to attend the session of the appeal panel. 21.  On 21 September 2009 the State Attorney’s Office of the Republic of Croatia (Državno odvjetništvo Republike Hrvatske) submitted a reasoned opinion proposing that the applicants’ appeals be dismissed. That opinion was not forwarded to the defence. 22.  On 13 January 2010 the Supreme Court informed the parties that a session of the appeal panel would be held on 9 March 2010. The parties were invited to attend, but it was expressly stated that the presence of the accused, who were in pre-trial detention and had a lawyer, would not be ensured, and that there would be no order for them to be brought to court. 23.  On 9 March 2010 the Supreme Court held a session in the presence of the applicants’ lawyers and the Deputy State Attorney of the Republic of Croatia (Zamjenik Glavnog državnog odvjetnika Republike Hrvatske, hereinafter, “the Deputy State Attorney”). That court stated that it had decided that it would not be useful to have the accused, who were represented by lawyers, brought from pre-trial detention. The Deputy State Attorney stated that he confirmed the proposal submitted under Article 373 § 2 of the Code of Criminal Procedure (see paragraph 21 above and 33 below). The parties stated that they had no objections as to how the session had been conducted or the content of the record of the session. The record of the session was signed by the appeal panel president and the clerk. 24.  On the same day the Supreme Court dismissed the applicants’ appeals and upheld their convictions. It held that all the secret surveillance orders had essentially provided sufficient reasoning. It explained that although the orders – apart from the first one issued against the fourth applicant – had been based on the Code of Criminal Procedure and not on the special legislation concerning organised crime (the OSCOC Act), that on its own did not render them unlawful. Section 41 and section 42(1) of the OSCOC Act provided for the possibility of ordering such measures. Also, the fact that the police had not submitted daily reports to the investigating judge concerning the execution of the orders did not render the secret surveillance orders unlawful, because a report had been submitted after the measures had been implemented. The court further held that the sovereignty of the Netherlands had not been violated by the interception of the second and third applicants’ telephone conversations, since the Croatian authorities had never issued a secret surveillance order against them. The secret surveillance orders had been lawfully issued in respect of several people in Croatia whom the second and third applicants – who had lived in the Netherlands at the time – had contacted. Since the second and third applicants had participated in the criminal activities of the persons under secret surveillance – activities which had amounted to the criminal offence proscribed under Article 181 of the Code of Criminal Procedure – such evidence (intercepted telephone conversations) could be used in the criminal proceedings against them. The Supreme Court also indicated that the trial court had correctly established the facts which were based on the applicants’ telephone conversations recorded by secret surveillance. 25.  The applicants challenged those findings by lodging constitutional complaints with the Constitutional Court (Ustavni sud Republike Hrvatske). They reiterated their complaints concerning the secret surveillance and the use of evidence so obtained in the criminal proceedings against them. The first, second and third applicants contended that the reasoned opinion of the State Attorney’s Office of the Republic of Croatia submitted during the appeal proceedings had not been forwarded to the defence. In addition, the first applicant complained that even though the Supreme Court had examined a number of legal and factual issues, including the question of an appropriate sentence which he had raised in his appeal, he had not been invited to attend the session of the appeal panel. The fourth applicant also complained that the domestic courts had failed to call two defence witnesses he had wished to call. 26.  On 9 January 2014 the Constitutional Court dismissed the applicants’ constitutional complaints, upholding the findings of the Supreme Court. As to the first, second and third applicants’ complaint concerning the reasoned opinion of the State Attorney’s Office of the Republic of Croatia not being forwarded to the defence, the Constitutional Court noted that at the session of the appeal panel the Deputy State Attorney had reiterated the arguments submitted in the opinion in question. The applicants’ lawyers had attended the session and had therefore had the opportunity to have knowledge of and comment on those submissions. As to the fourth applicant’s complaint that the trial court had refused to hear two witnesses whom he had wished to call, the Constitutional Court noted that the trial court had given reasons for doing so. 27.  The decisions of the Constitutional Court were served on the lawyer representing the first, second and third applicants and the lawyer representing the fourth applicant on 21 and 24 February 2014 respectively.