CCPR/C/79/Add.102 page 5 23. The Committee is concerned that the substitute prison system (Daiyo Kangoku), though subject to a branch of the police which does not deal with investigation, is not under the control of a separate authority. This may increase the chances of abuse of the rights of detainees under articles 9 and 14 of the Covenant. The Committee reiterates its recommendation, made after consideration of the third periodic report, that the substitute prison system should be made compatible with all requirements of the Covenant. 24. The Committee is concerned that rule 4 of the Habeas Corpus Rules under the Habeas Corpus Law limits the grounds for obtaining a writ of habeas corpus to (a) the absence of a legal right to place a person in custody and (b) manifest violation of due process. It also requires exhaustion of all other remedies. The Committee is of the view that rule 4 impairs the effectiveness of the remedy for challenging the legality of detention and is therefore incompatible with article 9 of the Covenant. The Committee recommends that the State party repeal rule 4 and make the remedy of habeas corpus fully effective without any limitation or restriction. 25. The Committee is deeply concerned about the fact that a large number of the convictions in criminal trials are based on confessions. In order to exclude the possibility that confessions are extracted under duress, the Committee strongly recommends that the interrogation of the suspect in police custody or substitute prisons be strictly monitored, and recorded by electronic means. 26. The Committee is concerned that under the criminal law, there is no obligation on the prosecution to disclose evidence it may have gathered in the course of the investigation other than that which it intends to produce at the trial, and that the defence has no general right to ask for the disclosure of that material at any stage of the proceedings. The Committee recommends that, in accordance with the guarantees provided for in article 14, paragraph 3, of the Covenant, the State party ensure that its law and practice enable the defence to have access to all relevant material so as not to hamper the right of defence. 27. The system in paragraph concerned Committee is deeply concerned at many aspects of the prison Japan which raise serious questions of compliance with articles 2, 3 (a), 7 and 10 of the Covenant. Specifically, the Committee is with the following: (a) Harsh rules of conduct in prisons that restrict the fundamental rights of prisoners, including freedom of speech, freedom of association and privacy; (b) Use of harsh punitive measures, including frequent resort to solitary confinement;