CAT/C/31/D/189/2001 Page 15 authorities in support of his application for political asylum, since the certificate, from the “leader of the ENNAHDA movement”, confirmed his membership of the “movement”. 8.7 Concerning the allegations relating to prison conditions, and in particular the arrangements for transfers between one prison and another, which the complainant considers an abuse, the State party points out that, in keeping with the applicable regulations, transfers are decided upon in the light of the different stages of the proceedings, the number of cases and the courts which have competence for specific areas. The prisons are grouped in three categories: for persons held awaiting trial; for persons serving custodial sentences; and semi-open prisons for persons found guilty of ordinary offences, which are authorized to organize agricultural labour. According to the State party, as the complainant had changed his status from that of remand prisoner to that of a prisoner serving a custodial sentence, and bearing in mind the requirements as to investigations in his case or in other similar cases, he was transferred from one prison to another, in accordance with the applicable regulations. The conditions in which the complainant was held, wherever he was held, were in keeping with the prison regulations governing conditions for holding prisoners in order to ensure prisoners’ physical and moral safety. The State party points out that prisoners’ rights are scrupulously protected in Tunisia, without any discrimination, whatever the status of the prisoner, in a context of respect for human dignity, in accordance with international standards and Tunisian legislation. Medical, psychological and social supervision is provided, and family visits are allowed. The State party maintains that the conditions in which the complainant was held were in keeping with Tunisian regulations governing prison establishments, which conform to relevant international standards. 8.8 Contrary to the allegations that the medical consequences suffered by the complainant are due to torture, the State party rejects any causal link. It notes in particular that the medical certificate recording a neuropsychiatric disorder, which was produced by the complainant, dates from 29 July 1999, that is, some 10 years after the “incidents”. The State party also cites the psychological problems to which the complainant referred in court (para. 8.5). In addition, according to the State party, the complainant, contrary to his allegations, enjoyed proper medical supervision and appropriate care during his stay at the prison of Borj Erroumi. 8.9 Concerning the allegations that he was denied visits, according to the State party the complainant regularly received visits from his brothers, his uncle, his father and his mother, in accordance with the prison regulations, as demonstrated by the visitors’ records in the prisons in which he was held. 8.10 Concerning the allegations relating to article 11 of the Convention, the State party rejects them and refers to systematic monitoring11 of compliance with rules, instructions, methods and practices of interrogation and provisions relating to the holding12 and treatment of persons who have been arrested, detained or imprisoned.13 11 In addition to legislation, protective institutional machinery has been set up by stages, including surprise visits to prisons by the Chairman of the Higher Committee for Human Rights and Fundamental Freedoms, and the creation on 31 July 2000 of a post of “judge for the enforcement of sentences” who is responsible for closely monitoring the enforcement of custodial sentences and conducting periodic visits to prisons. 12 Act No. 99-90 of 2 August 1999 amended and supplemented a number of provisions of the Code of Criminal Procedure, and in particular reduced the length of police custody to three days, renewable once only for a further three days. Under the Act, criminal investigation officers may not hold a suspect for more than three days; they