A/HRC/33/51 Disappearances occurring during the detention of migrants27 or the execution of deportation procedures (ii) 58. The study will also take into consideration instances where migrants disappear while they are detained or during the execution of deportation procedures. Indeed, migrants who are captured in a transit or destination State, and detained under administrative or criminal proceedings, may sometimes disappear. This could be in part be due to the lack of transparency or to the secrecy of such detention, and the very limited access to the justice system that migrants often have in this context.28 The Group will address how disappearances can occur in such contexts, as well as during the execution of deportations. 59. Similarly, many cases were reported where migrants were deported to their State of origin or another State, where they face enforced or involuntary disappearances or where they risk being subjected to that practice, in contravention of the international law principle of non-refoulement.29 In that process, it has been observed that formal deportation procedures, including the assessment of risk of persecution in the country of origin, are sometimes not duly respected and, as a result, migrants are not registered and are unable to lodge asylum claims. (iii) Enforced disappearances of migrants by private actors acting on behalf of, or with the support, direct or indirect, consent or acquiescence of the State 60. There have been a number of reported cases of disappearances of migrants while they transit in a third State or upon arrival in the State of destination (see CED/C/MEX/CO/1, paras. 23-24).30 In some instances, migrants are arrested and detained by State agents (migration officers or security forces) and later disappeared. In other instances, captured migrants are delivered by State agents to private actors, often members of organized criminal groups and, as such, are also the object of enforced disappearances, often trapped in trafficking networks for the purpose of economic or sexual exploitation. (c) Factors that contribute to the enforced disappearances of migrants 61. The Working Group will analyse in greater detail factors that contribute to enforced disappearances of migrants, including them being exposed to greater situations of vulnerability and to multiple forms of discrimination and the impact of State migratory and security policies, as well as the existence of obstacles in the search for justice and truth regarding such human rights violations. (i) Vulnerability and discrimination 62. The Working Group highlighted the particular vulnerability of migrants to enforced disappearances in past reports, in particular due to obstacles facing the judicial protection of their rights, as well as the irregular nature of their migration status (see A/HRC/19/58/Add.2, para. 69). 63. Some migrants enter irregularly and are thus not recorded, and others enter in a regular manner but remain unaccounted for because of the lack of procedures established at the borders of many countries. That is exacerbated by the lack of effective laws and protection programmes, as well as ineffective judicial remedies available to them (see 27 28 29 30 10 See A/HRC/20/24. See, similarly, Inter-American Commission on Human Rights, “Human Rights of migrants and other persons in the context of human mobility in Mexico”, OEA/Ser.L/V/II Doc48/13 (2013), p. 42. See art. 8 of the Declaration. See also A/HRC/33/53/Add.1, para. 14.