A/HRC/15/29 based arguments, such as those relating to general migration control, cannot override best interests considerations”.38 This implies in turn that an effective mechanism to determine the best interests of the child should be in place before return can be contemplated. 49. International law prohibits collective expulsions, reasoning that there is a risk that such expulsions will be tainted with discrimination and arbitrariness, and will therefore be inherently unlawful.39 Article 22 of the Convention on the Protection of the Rights of All Migrant Workers and Members of Their Families specifically prohibits the collective expulsion of migrant workers and members of their families, and provides some safeguards in case of expulsion. Regional instruments, such as the Protocol No. 4 to the European Convention for the Protection of Human Rights, similarly prohibit the collective expulsion of non-nationals. E. Detention 50. The absence of a child and adolescent perspective within migration-related detention policies means that children are often treated, and detained, as adults, including in punitive detention meant to deter future irregular arrivals. In some situations, children are placed in immigration detention as a substitute for care arrangements. 51. Children in immigration detention are often exposed to severely inadequate conditions, including deplorable living conditions, lack of adequate medical care (including psychological care), physical and sexual abuse and violence, overcrowding and inadequate nutrition. They can be detained along with unrelated adults, or arbitrarily separated from their parents or other family members. While all migrants can be detained in inappropriate facilities, such as prisons which house convicted criminals, children who are detained in immigration detention in addition rarely have access to adequate education, play and leisure facilities, and staff who are trained to respond to the specific needs of migrant children. Children in immigration detention will often be traumatized and have difficulty understanding why they are being “punished” despite having committed no crime.40 52. International law provides that the detention of children, including children in the context of migration, should generally be avoided.41 The Special Rapporteur on the human rights of migrants has affirmed that it is never in the best interests of children to be detained.42 Children should not be detained based on their migratory status or irregular entry to the country.43 53. Where it is deemed to be absolutely necessary, children should only ever be detained as a measure of last resort, this detention must always be justified in law, and it must be for the shortest possible period of time.44 A maximum period of detention must be set in law. There should be a judicial review of the decision to detain, and the child must be able effectively to challenge the legality of their detention before a court or other competent body, and to have a prompt decision.45 38 39 40 41 42 43 44 45 General comment No. 6, para. 86. Human Rights Committee, general comment No. 15 on the position of aliens under the covenant. International Organization for Migration, “Human Rights of Migrant Children”, International Migration Law, No. 15 (2008), p. 33. Convention on the Rights of the Child, art. 37. See also Committee on the Rights of the Child, general comment No. 10 on children’s rights in juvenile justice. A/HRC/11/7, para. 62. Committee on the Rights of the Child, general comment No. 6, para. 61. Convention on the Rights of the Child, art. 37(b). International Covenant on Civil and Political Rights, art. 9. 13