4.  The applicant was born in 1974 and lives in Ząbki. 5.  In 2001 the police conducted an operation to disband several organised criminal gangs that were acting in and around Warsaw, stealing luxury cars with a view to selling them in the countries of the former Soviet Union. There were about five such groups, cooperating closely with each other and closely connected with Poland's most dangerous armed criminal groups: the Pruszków mafia and the Wołomin mafia. 6.  The applicant was arrested on 18 December 2001 on suspicion of thefts, robberies committed with extreme brutality and membership of a criminal gang. He was remanded in custody by the decision of the Warsaw District Court of 20 December 2001. 7.  At that time the Warsaw Regional Prosecutor was conducting an investigation in respect of more than fifty other members of the criminal gangs mentioned above. Forty-two of them were held in custody. The investigation was complex and time-consuming, given that the criminal gangs collaborated closely with many persons who were to be questioned by the prosecutors, for example, receivers of stolen goods, persons hiding stolen cars or persons tracking cars which were to be stolen, among others. 8.  In addition, the prosecutor opened an investigation in respect of several police officers from Warsaw and surrounding towns on charges of corruption and helping the criminal groups' members to evade the law. 9.  On 5 December 2002 a bill of indictment against the applicant and fifty-nine other co-accused (members of five cooperating criminal gangs) was lodged with the Warsaw District Court. The evidentiary material was presented in 99 case files. The applicant was charged with membership of a criminal gang, carrying out multiple robberies and thefts committed with extreme brutality. The criminal gang, of which the applicant was a member, was known for its violence and ruthlessness and for the illegal trafficking of firearms. 10.  On 6 January 2003 the Warsaw District Court held the first hearing. The following hearings were held by the District Court:
In 2003, on: 23 and 30 May; 23 and 24 June; 1, 4, 7, and 8 July; 13, 18, 22, and 25 August; 5, 12, 15, and 19 September; 10, 20, 21, 23, 24, and 31 October; 17 November; 5, 22, and 23 December 2003;
In 2004, on: 5 and 26 January; 16, 17, 19, and 20 February; 8 and 9 March; 1 and 9 April; 14, 18, 21, and 25 May; 3, 7, 14, and 23 June; 5 July;10, 25, and 31 August; 3 and 6 September; 7, 8, and 15 October; 2 and 9 November; 7, 8, 10, 13, and 18 December 2004. In total, sixty hearings were held by the District Court. 11.  During the trial the District Court examined a wide range of evidentiary material, ordered medical expert opinions on the accuseds' mental health and expert opinions in the field of dactyloscopy, conducted inquiries in the accuseds' respective neighbourhoods, inspections of the crime scenes and garages where the stolen cars had been hidden and assessments of the accuseds' assets. The proceedings involved taking evidence from a considerable number of witnesses and victims and from one key witness. 12.  The applicant's pre-trial detention was prolonged several times by the District Court. The decisions were issued, inter alia, on 15 March, 17 June, 13 December 2002; 23 May, 25 August, 17 November, 5 December, 15 December 2003; 20 February, 7 June, 6 September, 9 November, 18 December 2004; 16 March, 15 July, 30 September, 14 November 2005; 13 February, 8 May and 2 August 2006. In its decisions the court underlined that there was a strong likelihood that the applicant had committed the crimes, confirmed in particular by the testimonies of a key witness and a co-accused, and considered that there was a reasonable risk that the applicant would tamper with the evidence, given that he had had close connections with the other co-accused. The court also made reference to the investigative acts already carried out and gave a precise indication of the evidence that still had to be taken. Consequently, it decided that it was indispensable to separate the applicant from the other suspects, the witnesses and the evidence which had not yet been secured. The court also relied on the serious nature of the charges against the applicant and the severity of the penalty he faced. No special circumstances dictated the lifting of the detention. 13.  The applicant unsuccessfully appealed against the above mentioned decisions. 14.  From 29 May 2002 to 14 June 2004 the applicant served a prison sentence imposed on him in separate proceedings. 15.  On 18 December 2004 the District Court imposed a sentence on fifty of the co-accused. The applicant was found guilty of most of the charges laid against him and sentenced to 9 years' imprisonment. 16.  The applicant's lawyer lodged an appeal against the judgment on 5 December 2006. 17.  On 6 June 2006 the case file, comprising 149 volumes, was transferred to the second-instance court. On 22 November 2006 the Court of Appeal partly amended the judgment, sentencing the applicant to 8 years' imprisonment. 18.  On 4 September 2007 the Supreme Court dismissed the cassation appeal.
The monitoring of the applicant's correspondence 19.  The applicant submitted that while in detention on remand in the course of the above-mentioned proceedings, his correspondence had been censored. As proof thereof he provided a copy of an envelope dated 14 December 2005 of a letter sent to him by his lawyer and bearing a stamp “censored on 23 December 2005” (“ocenzurowano, 23.12.2005”) and an illegible signature, and a copy of the envelope of the letter from the Court dated 14 November 2005 with several stamps of the penitentiary institution on it, however with no clear indication of censorship.