CAT/OP/27/1 to have their complaints promptly and impartially e xamined, to defend their rights and to challenge the legality of their detention or treatment. 16 55. One of the most persistent problems encountered by the Subcommittee in the course of its visits is the poor material conditions existing in places of detent ion, which are often accompanied by overcrowding. This serious problem also arises in centres of deprivation of liberty for women. 56. Nevertheless, since it is a critical and persistent problem, it is worth recalling that detention conditions not only raise issues of cruel, inhuman or degrading treatment or punishment but in some circumstances can also be a means of torture, if used in a manner which accords with the provisions of article 1 of the Convention. 17 57. Accordingly, recommendations regarding conditions of detention play a critical role in effective prevention and will touch on a wide variety of issues, including matters relating to physical conditions, the reasons for, and levels of, occupancy and the provision of, and access to, a wide range of facilities and services. 18 16 17 18 GE.16-00603 See CAT/C/GC/2, para. 13. See CAT/OP/12/6, para. 5 (d). Ibid. 9/9