TK-31-10-681-EN-C FRA - European Union Agency for Fundamental Rights Schwarzenbergplatz 11 1040 - Wien Austria Tel.: +43 (0)1 580 30 - 0 Fax: +43 (0)1 580 30 - 691 Email: information@fra.europa.eu fra.europa.eu doi: 10.2811/85200 This report deals with deprivation of liberty of irregular migrants pending return. The grounds for any deprivation of liberty must be set forth in law in a clear and exhaustive manner. Even when based on legitimate grounds, detention has to fulfil additional requirements in order not to be arbitrary. For example, return proceedings have to be carried out with due diligence and there must be realistic prospects of removal. Indefinite pre-removal detention is arbitrary. Detention can also become arbitrary if the purpose for which it was ordered can be achieved by applying less restrictive measures, such as regular reporting requirements or residence restrictions A number of procedural safeguards have been set up to reduce the risk of unlawful or arbitrary detention. These include the right to be informed of the reasons for detention in a language the person understands, the right to judicial review of the detention decision and legal assistance.