A/65/44 Prosecutor, take steps to ensure that solitary confinement remains an exceptional measure of limited duration, in line with international standards. Imposition of differing detention regimes (27) The Committee is concerned to note that the Prison Act of 24 November 2009 appears to give the prison authorities broad discretion, under article 89, to place prisoners under different detention regimes on the basis of a classification according to subjective criteria such as a prisoner’s personality or the danger he might represent. A regime of this kind can by definition lead to arbitrary treatment of prisoners in the course of their sentences. It is possible, for example, to envisage a situation in which a disciplinary punishment or denial of access to certain entitlements while in detention could, if repeated and imposed without due justification or in an arbitrary manner, constitute cruel, inhuman or degrading treatment or punishment under article 16 (art. 16). The Committee encourages the State party to take appropriate steps to exercise supervision over the discretionary element of the powers vested in the prison authorities, and the corresponding risk of arbitrary action. Such supervision should be exercised through regular visits by existing independent supervisory mechanisms, which should in turn immediately report to the competent judicial authorities any irregularity or practice that could be considered an arbitrary measure, particularly when the measure in question involves solitary confinement. Body searches (28) The Committee takes note of the information submitted by the State party to the effect that the current search procedure under the Prisons Act of 24 November 2009 is more restrictive than the previous one. In the light of two judgements of the European Court of Human Rights (in Khider v. France and Frérot v. France), the Committee nevertheless remains concerned at the intrusive and humiliating nature of body searches, especially internal. The Committee is further concerned that the procedure regulating the frequency and methods of searches in prisons and detention centres is determined by the prison authorities themselves. Furthermore, the Committee is concerned at the lack of information available regarding the follow-up to Khider v. France and Frérot v. France, particularly at the lack of indicators allowing an assessment to be made of any future risk of a violation of article 16 occurring as a result of body searches (art. 16). The Committee recommends that the State party exercise strict supervision of body search procedures, especially full and internal searches, by ensuring that the methods used are the least intrusive and the most respectful of the physical integrity of persons, and in all cases in compliance with the terms of the Convention. The Committee further recommends the implementation of the electronic detection methods announced by the State party, and the widespread use of such mechanisms, in order to eliminate the practice of body searches altogether. Secure detention (29) The Committee is deeply concerned about so-called secure detention (rétention de sûreté), established by Act No. 2008-174 of 25 February 2008 on secure detention, and the declaration of exemption from criminal responsibility for reason of mental disorder, and supplemented by Act No. 2010-242 of 10 March 2010, which seeks to reduce the risk of criminal recidivism and establishes various provisions of criminal procedure. Besides the obvious challenge to the principle of legality in criminal proceedings that this measure implies, due to the lack of objectively definable and predictable material criteria, the lack of a causal link between the offence and the possible penalty, and the fact that it can be applied retroactively, the measure, which does not appear to set a time limit on detention, is also likely to raise issues under article 16 (art. 16). GE.10-44721 97