MONITORING PLACES OF DETENTION : A PRACTICAL GUIDE FOR NGOS 24 Prevention of Torture can really be said to have access at any time to any place of detention in any State Party to the European Convention for the Prevention of Torture. With the adoption of the Optional Protocol to the United Nations Convention against Torture, a Sub-Committee to the Committee against Torture will be established. It will be able to visit places where persons are deprived of their liberty in the States Parties. (see footnote 5). 4. THE INVOLVEMENT OF NATIONAL NGOS IN MONITORING CONDITIONS OF DETENTION: A NECESSITY Why should non-governmental organisations be encouraged to become involved in monitoring conditions of detention, given that different types of control are already provided and, in theory, implemented at the national level? The main reasons are as follows: ■ Inspections/monitoring by the State of its own organs is necessary but, by definition, not independent; ■ External control systems are not always effective, or are not frequent enough to fulfil their fundamental role as a regulating mechanism; ■ The inspections are sometimes superficial; formal or bureaucratic aspects are given precedence over questions relating to the organisation and handling of the persons detained, which are more difficult to examine and more delicate to treat; ■ The checks carried out by international bodies, while necessary, do not have the requisite character of permanence.