A/HRC/30/37 (d) When asylum seekers, immigrants or refugees are subjected to prolonged administrative custody without the possibility of administrative or judicial review or remedy; (e) When the deprivation of liberty constitutes a violation of international law for reasons of discrimination based on birth, national, ethnic or social origin, language, religion, economic condition, political or other opinion, gender, sexual orientation, disability or other status, and which is aimed at or may result in ignoring the equality of human rights. 11. In deliberation No. 9 concerning the definition and scope of arbitrary deprivation of liberty under customary international law (see A/HRC/22/44, paras. 37-75), the Working Group restated its constant jurisprudence on the prohibition of all forms of arbitrary deprivation of liberty, and demonstrated that it is general practice accepted as law, constituting customary international law and a peremptory norm (jus cogens). In its annual report for 2013 (A/HRC/27/48), the Working Group restated that the prohibition of arbitrariness in the deprivation of liberty requires a strict review of the lawfulness, necessity and proportionality of any measure depriving anyone of their liberty; this standard of review is applicable at all stages of legal proceedings. In the interactive dialogue held at the twenty-second session of the Council, States gave general support for the conclusions of the deliberation. The present Basic Principles and Guidelines adopt the criteria laid out by the International Court of Justice in its judgement of 20 July 2012 concerning Questions relating to the Obligation to Prosecute or Extradite (Belgium v. Senegal) when confirming the status of the prohibition of torture as a peremptory norm (jus cogens). The prohibition of arbitrary detention is supported by the widespread international practice and on the opinio juris of States. It appears in numerous international instruments of universal application and has been introduced into the domestic law of almost all States. Lastly, arbitrary detention is regularly denounced within national and international forums. 12. For the purposes of the present Basic Principles and Guidelines, deprivation of liberty is regarded as “unlawful” when it is not on such grounds and in accordance with procedures established by law. It refers to both detention that violates domestic law and detention that is incompatible with the Universal Declaration of Human Rights, general principles of international law, customary international law, international humanitarian law, as well as with the relevant international human rights instruments accepted by the States concerned. It also includes detention that may have been lawful at its inception but has become unlawful because the individual has served the entire sentence of imprisonment, following the expiry of the period for which the person was remanded into custody or because the circumstances that initially justified the detention have changed. 13. States employ different models to regulate the exercise of the right to bring proceedings before a court to challenge the arbitrariness and lawfulness of detention and to obtain appropriate remedies without delay. Although no specific model is endorsed in the principles and guidelines, States are encouraged to guarantee this right in law and in practice. 14. The Basic Principles and Guidelines are based on the recognition that States should take a series of measures to establish and/or to reinforce the procedural safeguards provided to persons deprived of their liberty. 15. The Working Group recalls the Preamble to the Charter of the United Nations, which refers to the determination of the peoples of the United Nations “to establish conditions under which justice and respect for the obligations arising from treaties and other sources of international law can be maintained”. One of the purposes of the United Nations is “to maintain international peace and security” and, to that end, “to take effective collective measures for the prevention and removal of threats to the peace, and for the 4