A/HRC/27/47 International Covenant on Civil and Political Rights, this includes the right to challenge the legality of detention before a court in proceedings affording fundamental due process rights. It concluded that “any person deprived of his or her liberty must enjoy continued and effective access to habeas corpus proceedings, and any limitations to this right should be viewed with utmost concern” (ibid.). 32. More recently, a joint study on global practices in relation to secret detention in the context of countering terrorism was prepared by the Special Rapporteur on the promotion and protection of human rights and fundamental freedoms while countering terrorism, the Special Rapporteur on the question of torture, the Chair-Rapporteur of the Working Group on Enforced or Involuntary Disappearances and the Vice-Chair of the Working Group on Arbitrary Detention (A/HRC/13/42). They concluded that secret detention was irreconcilably in violation of international human rights law, including during states of emergency and armed conflict, and in violation of international humanitarian law during any form of armed conflict. Secret detention violates the right to personal liberty and the prohibition of arbitrary arrest or detention. No jurisdiction should allow for individuals to be deprived of their liberty in secret for potentially indefinite periods, outside the reach of the law, without the possibility of resorting to legal procedures, including habeas corpus (A/HRC/16/47, para. 54). The group of experts underlined the centrality of “effective habeas corpus reviews by independent judicial bodies” to ensuring respect for the right to personal liberty (A/HRC/13/42, para. 292 (b)). The group recommended that “domestic legislative frameworks should not allow for any exceptions from habeas corpus, operating independently from the detaining authority and from the place and form of deprivation of liberty … The law should foresee penalties for officials who refuse to disclose relevant information during habeas corpus proceedings” (ibid.). C. Exercise of the right by vulnerable groups 33. Further to the procedural guarantees that apply to all persons deprived of their liberty, additional safeguards are necessary for the exercise of the right to challenge the lawfulness of detention by particular vulnerable groups, including by child detainees, by detained migrants, including asylum seekers, and by persons detained involuntarily on health grounds. 1. Child detainees 34. The Convention on the Rights of the Child, in article 37 (b), obligates State parties to ensure that “no child shall be deprived of his or her liberty unlawfully or arbitrarily. The arrest, detention or imprisonment of a child shall be in conformity with the law and shall be used only as a measure of last resort and for the shortest appropriate period of time”. It guarantees to every child deprived of his or her liberty “the right to prompt access to legal and other appropriate assistance, as well as the right to challenge the legality of the deprivation of his or her liberty before a court or other competent, independent and impartial authority, and to a prompt decision on any such action” (art. 37 (d)). 35. Rule 13 of the United Nations Rules for the Protection of Juveniles Deprived of their Liberty, on the right to challenge the lawfulness of detention, guarantees that “juveniles deprived of their liberty shall not for any reason related to their status be denied the civil, economic, political, social or cultural rights to which they are entitled under national or international law, and which are compatible with the deprivation of liberty.” Rule 7.1 of the United Nations Standard Minimum Rules for the Administration of Juvenile Justice (Beijing Rules) calls for the guarantee of basic procedural safeguards at all stages of the proceedings, including the right to appeal to a higher authority. The issue of release is to be considered by a judge or other competent official or body without delay (rule 10.2). In the 11