“Foreigners in detention” are defined as those who are detained in a State of which they are not nationals. In some countries, foreigners represent a minority, while in others they are by far the majority. It is important to distinguish between foreigners detained following a criminal process and those detained for immigration-related reasons. 

Criminal process: Foreigners are found in criminal detention facilities having been accused of or convicted for crimes under the national law of the country; having been detained at the request of another country pending extradition/deportation; or having been detained/serving a sentence by an International tribunal. In some countries, unauthorised or irregular entry or stay in the territory without proper documentation is criminalised and leads to imprisonment.

Administrative/immigration process due to their migration status: In some countries, violations of the immigration law (alleged breach of conditions of entry, stay or residence of a territory) leads to administrative detention (also called retention), which describes arrest and detention without charge or trial ordered by the administrative authorities rather than a court. Authorities usually detain migrants to verify their identity; during the refugee determination process; and/or when a deportation decision has been made to ensure the migrant does not abscond. Today, use of the term "immigration detention" is growing despite the fact that it should only be a measure of last resort. When detention is used, it is incumbent on the State to mitigate the loss of liberty as far as possible by ensuring that the treatment and conditions are respectful of the dignity and non-criminal status of immigration detainees.

Foreigners under the criminal system are usually detained in any detention facility alongside nationals of the country, such as police stations or prisons. They can be vulnerable at many levels and face heightened risks of abuse or ill-treatment, as they are outside their countries of origin or nationality, unfamiliar with the legal context or even with the language. They may not have a strong family or community support network available to them. This can have serious psychological effects on a detainee, as well as deprive them of external physical support, such as food and clothing.

In addition to visits and other means of communications (e.g. telephone, email, post), authorities have a legal obligation under the Vienna Convention to notify the diplomatic or consular representatives of foreign detainees, including migrants, as long as the detainee consents to this notification.

In some situations, foreigners in detention are grouped by nationality and it is not uncommon that tensions arise between national groups.

To a varying degree, foreigners will struggle with the language spoken in the place of detention. For example, one of the key procedural safeguards is that detainees are informed on arrival of the reasons why they are detained and the process to appeal their detention. This right can only be fully respected if detainees are provided with the information in a language that they understand and/or that they have access to an interpreter.

States should take positive actions on behalf of foreign detainees, such as ensuring that key documents (e.g. detainees’ rights, internal rules, complaints system) are translated in various languages and providing diets that cater for different cultural requirements. Such measures mitigate the risk of isolation of foreign detainees due to language barriers and religious and cultural practices.

These risks can be further exacerbated for persons with special needs or those who in situations of vulnerability, such as: women; children, including unaccompanied or separated children; members of different ethnic/tribal/social groups detained together; victims of torture or trauma; trafficked persons; smuggled migrants; stateless persons; persons with disabilities; elderly persons; LGBTI persons; or those with urgent medical needs.

The authorities should recognise and address the specific needs of foreigners in detention. Foreign detainees should not be automatically placed in remote places of detention by simple assumption that they have no family contacts. Similarly they should not be denied leave solely because they have no home to go to. It is the duty of authorities to ensure that foreigners are not discriminated against and that positive measures are in place to prevent discrimination.

Legal standards

Further reading