An investigation has been launched into the death of a detainee at an immigration removal centre (IRC).
The detainee died at Harmondsworth IRC in west London on Tuesday.
A UK Border Agency spokesman said: "This death is being investigated so it would be inappropriate to comment at this stage.
"We will work with the prisons and probation ombudsman during the investigation."
Harmondsworth IRC, near Heathrow Airport, is a purpose-built, long-term centre which holds up to 615 detainees pending their removal from the UK.