5.  The applicant was born in 1965 and lives in Ҫanakkale. 6.  On 26 June 2005 following an undercover police operation, the applicant was arrested on suspicion of selling illegal drugs. 7.  According to the police records issued at the Avcılar police station, after having been informed by an unidentified source that the applicant had been trafficking illegal drugs, two officers contacted him by telephone to purchase a fix of heroin for 40 Turkish liras (TRY)[1]. Subsequently, the officers met the applicant at an address they had determined on the telephone, where he tried to sell them a light brown substance, which they suspected to be heroin, wrapped in a piece of paper. In exchange, the officers gave him TRY 40 in banknotes, the serial numbers of which had been noted before. The applicant was arrested immediately afterwards. 8.  Following his arrest, the police found four other small packages of the same substance and a syringe on the applicant. The police records noted that the total weight of the substance, including that sold to the police officers, was 2.2 grams. The substance was then sent to the Istanbul Criminal Police Laboratory for chemical examination. 9.  On the same day the applicant gave statements to the police in the presence of a lawyer. He maintained that the police officers had searched him while he had been sitting in front of his house and found a syringe and four small packages of heroin, which he had bought from a certain A. for TRY 120 two days before, for his own personal use. The applicant denied that he had sold heroin and argued that he had only had TRY 35 on him at the time of the search. 10.  Later that day, the Avcılar Directorate of Security informed the officers at the Avcılar police station that a warrant had been issued for the applicant’s arrest following a previous conviction by the Küçükçekmece Assize Court for using illegal drugs. 11.  On 27 June 2005 the Istanbul Criminal Police Laboratory established that the light brown substance, which had a net weight of 2.1 grams, was indeed heroin. 12.  On the same day the applicant was questioned by the Küçükçekmece Criminal Magistrates’ Court. He submitted that he had been using drugs for more than twenty years and that he purchased a certain amount of heroin from A. every four days for his own consumption. The investigating judge held that he should be placed in detention pending the outcome of the proceedings. 13.  Subsequently, on 11 July 2005 the Bakırköy public prosecutor filed an indictment with the Bakırköy Assize Court, accusing the applicant of possession of and trafficking illegal drugs under Article 188 (3) of the Criminal Code (Law no. 5237). 14.  In the meantime, it was established that the applicant had previous convictions for using and selling heroin and for attempted theft. 15.  During the course of the proceedings before the Bakırköy Assize Court, at a hearing on 14 September 2005 the applicant maintained that he was merely an addict and that the police records falsely stated that he had accepted money in exchange for drugs. 16.  At a subsequent hearing on 14 October 2005 two police officers made statements. One of them submitted that after being informed that the applicant had been selling drugs, another police officer, C.D., had called the applicant on the telephone and arranged a meeting to buy a certain amount of the illegal substance. The applicant’s lawyer argued that the police evidence was unlawful in that the officers had conducted the operation without any judicial supervision and that their acts amounted to inciting the commission of an offence. In that respect, he requested that telephone records be examined in order to establish whether the events had unfolded as stated in the police records. 17.  On 6 December 2005 the court heard evidence from police officer C.D., who maintained that he had called the applicant on his mobile telephone and told him that he wished to buy drugs. According to his statement, the applicant had agreed and arranged a meeting. He had then met the applicant down a side road, where they had exchanged the drugs for the banknotes with noted serial numbers. 18.  At the hearing on 3 February 2006 the Bakırköy Assize Court heard evidence from witness M.T. at the request of the applicant. M.T. maintained that he knew the applicant to be an addict like himself and that he had never heard of him selling drugs. M.T. added that the applicant would sometimes purchase drugs for him too when he went to buy his dose, which he would pay for afterwards. He stated that one of their friends, Ӧ., was not on good terms with the applicant, but that he did not know whether Ӧ. was the informant. 19.  On 1 March 2006 the mobile network operator submitted a list of the telephone numbers the applicant had been in contact with prior to his arrest. Nevertheless, at a hearing on 31 March 2006 the court rejected the request of the applicant’s lawyer to determine to whom those numbers belonged, noting that it would have no effect on the judgment. 20.  At the same hearing, the public prosecutor submitted his observations. He maintained that on the basis of witness statements, the applicant’s past convictions and the substance found on him, he must be found guilty as charged as it was established that he had been arrested while trying to sell illegal drugs to police officers. In response, the applicant’s lawyer reiterated that the evidence relied on by the public prosecutor had been obtained unlawfully. 21.  On 26 May 2006 the Bakırköy Assize Court found the applicant guilty of trafficking drugs and sentenced him to six years and three months’ imprisonment pursuant to Article 188 (3) and (4) of the Penal Code (Law no. 5237). The court took into account the statements of the police officers, the testimony of M.T. and the evidence resulting from the police operation. 22.  On 25 December 2006 the Court of Cassation upheld the judgment of the first-instance court. 23.  On 21 April 2010 the applicant was granted conditional release.