Report of the Working Group on Arbitrary Detention: United Nations basic principles and guidelines on remedies and procedures on the right of anyone deprived of their liberty to bring proceedings before a court (A/HRC/30/37)

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. (…)

21. In every instance of detention, the burden of establishing the legal basis and the reasonableness, necessity and proportionality of the detention lies with the authorities responsible for the detention.

83. The State authorities shall establish before the court that:

(a) The legal basis for the detention in question is in conformity with international standards;

(b) The detention is justified in accordance with the principles of necessity, reasonableness and proportionality;

(c) Other less intrusive means of achieving the same objectives have been considered in the individual case.

85. When reviewing the arbitrariness and lawfulness of the detention, the court is empowered:

(a) To examine and act on the elements of inappropriateness, injustice, lawfulness, legality, predictability, and due process of law, and on basic principles of reasonableness, proportionality and necessity. Such an examination will take into account details such as age, gender and marginalized groups;

(b) To consider whether the detention remains justified or whether release is warranted in the light of all the changing circumstances of the detained individual’s case, including health, family life, protection claims or other attempts to regularize one’s status;

(c) To consider and make a pronouncement on whether alternatives to detention have been considered, including non-custodial alternatives to detention in accordance with the United Nations Standard Minimum Rules for Non-custodial Measures (the Tokyo Rules) and the United Nations Rules on the Treatment of Women Prisoners and Non-custodial Measures for Women Offenders (the Bangkok Rules);

(d) To take into account any orders of detention made subsequent to the commencement of court proceedings and prior to the rendering of the court’s decision.

86. When assessing whether the measures taken are in compliance with international standards, the prohibition of particular grounds of detention or forms of detention are to be complied with, and the needs of specific persons affected and any vulnerability are to be taken into consideration, given that the arbitrariness and unlawfulness of detention may include the unsuitability of detention for the persons in question.