C. Conditions of detention The question of conditions of detention has been a matter of concern for both the UN and regional systems. They have considered it with respect both to the right to freedom from torture and other cruel, inhuman or degrading treatment, and the right to respect for the inherent dignity of the human person. United Nations Although article 10 of the Covenant is not specified as non-derogable in article 4 of the same treaty, the Human Rights Committee has taken the view that the right of persons deprived of their liberty to be treated with humanity and with respect for the inherent dignity of the human person is nevertheless not subject to derogation: In those provisions of the Covenant that are not listed in article 4, paragraph 2, there are elements that in the Committee's opinion cannot be made subject to lawful derogation under article 4, [such as:] (a) All persons deprived of their liberty shall be treated with humanity and with respect for the inherent dignity of the human person. Although this right, prescribed in article 10 of the Covenant, is not separately mentioned in the list of non-derogable rights…, the Committee believes that here the Covenant expresses a norm of general international law not subject to derogation. This is supported by the reference to the inherent dignity of the human person in the preamble to the Covenant and by the close connection between articles 7 and 10…. --General Comment No. 29, CCPR/C/21/Rev.1/Add.11, para. 13 (2001). ***** In Polay Campos v. Peru, the Human Rights Committee examined a case where the victim had been detained in relation to alleged terrorist activities: Victor Polay Campos was detained incommunicado from the time of his arrival at the prison in Yanamayo until his transfer to the Callao Naval Base detention centre. The State party has not refuted this allegation; nor has it denied that Mr. Polay Campos was not allowed to speak or to write to anyone during that time, which also implies that he would have been unable to talk to a legal representative, or that he was kept in his unlit cell for 23 and a half hours a day in freezing temperatures. In the Committee’s opinion, these conditions amounted to a violation of article 10, paragraph 1, of the Covenant. As to the detention of Victor Polay Campos at Callao, it transpires from the file that he was denied visits by family and relatives for one year following his conviction, i.e. until 3 April 1994. Furthermore, he was unable to receive and to send correspondence. The latter information is corroborated by a letter dated 14 September 1993 from the International Committee of the Red Cross to the 36