A/HRC/45/16 left without any legal protection.10 Such secret and/or incommunicado detention cannot be part of the public health emergency measures introduced to combat a health-related crisis. IV. Necessity and proportionality of the deprivation of liberty 10. Any deprivation of liberty that has no legal basis or is not carried out in accordance with the procedure established by law is arbitrary. 11 Any law authorizing the deprivation of liberty must therefore be scrutinized. Any deprivation of liberty, even if it is authorized by law, may still be considered arbitrary if it is premised upon arbitrary legislation or is inherently unjust, relying for instance on discriminatory grounds, or if there is an overly broad statute authorizing automatic and indefinite deprivation of liberty without any standards or review, or the law does not specify clearly the nature of the conduct that is unlawful. 12 11. Moreover, even the lawful deprivation of liberty may still be arbitrary if such detention is not strictly necessary or a proportionate measure in pursuance of a legitimate aim. 13 In particular, States must be mindful that detention that initially satisfied the requirements of necessity and proportionality may no longer be justified insofar as the circumstances may have changed significantly. 12. The Working Group therefore calls upon all States to pay particular attention to the requirements of necessity and proportionality of deprivation of liberty in the context of public health emergencies, such as the newly emerging emergency related to the COVID-19 pandemic. 13. In particular, States should urgently review existing cases of deprivation of liberty in all detention settings to determine whether the detention is still justified as necessary and proportionate in the prevailing context of the COVID-19 pandemic. In doing so, States should consider all alternative measures to custody. 14. Pretrial detention should only be used in exceptional cases. 14 The current public health emergency puts an additional onus of consideration upon the authorities, as they must explain the necessity and proportionality of the measure in the circumstances of the pandemic. The Working Group recalls in particular that automatic pretrial detention of persons is incompatible with international law. 15 The circumstances of each instance of pretrial detention should be assessed; at all stages of proceedings, non-custodial measures should be taken whenever possible, and particularly during public health emergencies. 15. The Working Group is aware that COVID-19 mostly affects persons older than 60 years of age, pregnant women and women who are breastfeeding, persons with underlying health conditions,16 and persons with disabilities. It therefore recommends that States treat all such individuals as vulnerable. States should also refrain from holding such individuals in places of deprivation of liberty where the risk to their physical and mental integrity and life is heightened. 16. Lastly, noting that overcrowding and poor hygiene pose a particular risk of spreading COVID-19,17 States should seek to reduce prison populations and other detention populations wherever possible by implementing schemes of early, provisional or temporary release for those detainees for whom it is safe to do so, taking full account of non-custodial measures as 10 11 12 13 14 15 16 17 36 A/HRC/22/44, para. 60. International Covenant on Civil and Political Rights, art. 9. See also opinions Nos. 1/2017, 30/2017, 35/2018, 70/2018 and 49/2019; and Human Rights Committee, general comment No. 35, para. 11. A/HRC/22/44, para. 63. See also opinions Nos. 41/2017, 52/2018 and 62/2018, paras. 57–59; Human Rights Committee, general comment No. 35, para. 22. A/HRC/22/44, para. 61. See Human Rights Committee, general comment No. 35, paras. 11–12. A/HRC/19/57, paras. 48–58. See for example opinions Nos. 1/2018, 53/2018, 75/2018, 14/2019, 64/2019. See also Human Rights Committee, general comment No. 35, para. 38. See www.who.int/news-room/q-a-detail/q-a-coronaviruses. WHO Regional Office for Europe, “Preparedness, prevention and control of COVID-19 in prisons and other places of detention”.