A/HRC/27/47 commentary to the Beijing Rules, “other competent official or body” is defined as any person or institution in the broadest sense of the term, including community boards or police authorities having the power to release an arrested person. Rule 20.1 provides that “each case shall from the outset be handled expeditiously, without any unnecessary delay”. The commentary highlights as a paramount concern “the speedy conduct of formal proceedings in juvenile cases”. 36. The Committee on the Rights of the Child has interpreted the procedural guarantees in article 37 (d) of the Convention on the Rights of the Child in its general comment No. 10 (2007) on children’s rights in juvenile justice. The Committee specifies that the right to challenge the legality of the deprivation of liberty includes not only the right to appeal, but also the right to access the court, or other competent, independent and impartial authority or judicial body, in cases where the deprivation of liberty is an administrative decision. The right to a prompt decision means that a decision must be rendered as soon as possible, within or not later than two weeks after the challenge is made” (para. 84). With regard to the time limit between the commission of the offence and the decision by the court or other competent judicial body, the Committee stipulates that this should be much shorter than those set for adults, without compromising the full respect for the human rights of the child and legal safeguards (para. 52). The Committee regularly stresses the need for effective complaint procedures in general, and calls for the establishment of an “independent, childsensitive and accessible complaint system for children” within the context of the administration of juvenile justice (CRC/C/15/Add.193, para. 62 (j); CRC/C/15/Add.198, paras. 51 and 53). 2. Detained asylum seekers and migrants in an irregular situation 37. The Convention relating to the Status of Refugees, of 1951, and its 1967 protocol, lay down basic minimum standards for the treatment of refugees, including free access to the courts of law on the territory of States parties and the ability to submit evidence to clear himself, and to appeal to and be represented for the purpose before competent authority or a person or persons specifically designated by the competent authority (arts. 16 and 32 (2) of the Convention). 38. The Guidelines on the Applicable Criteria and Standards relating to the Detention of Asylum Seekers and Alternatives to Detention, of 2012, published by the United Nations High Commissioner for Refugees, include respect for the detainee’s right, either personally or through a representative, to challenge the lawfulness of detention before a court of law at any time (guideline 7). The guideline places the burden of proof for establishing the lawfulness of the detention on the authorities in question and requires that authorities establish the legal basis for the detention and justify it according the principles of necessity, reasonableness and proportionality, showing that less intrusive means of achieving the same objectives have been considered in the individual case (para. 47 (v)). 39. The Working Group on Arbitrary Detention has devoted particular attention to the situation of detained migrants, including migrants who are undocumented or in an irregular situation, asylum seekers awaiting the outcome of their asylum application and failed asylum seekers awaiting removal (Working Group opinions 55/2011 and 14/2011). Through its annual reports and in its deliberation no. 5 (1999) concerning the situation of immigrants and asylum seekers, the Working Group has set out a number of procedural guarantees for migrants in detention. In the case of absence, violation, circumvention or non-implementation of such procedural guarantees, the Working Group may conclude that the custody is arbitrary. 40. Procedural guarantees for detained migrants include notification of the custodial measure in writing, in a language understood by the asylum seeker or immigrant, stating the grounds for the measure, and setting out the conditions under which the asylum seeker or 12