A public watchdog is raising concerns about detaining asylum seekers who have served their sentences in a Leics jail.
The Independent Monitoring Board for Glen Parva Young Offenders Institution claims some are staying there rather than being sent to a detention centre.
The body now hopes to raise the issue with the Prisons Minister Paul Goggins.
The Home Office said the Immigration Service tried to ensure deportation coincided with the earliest release date, but this was not always possible.
The Independent Monitoring Board, formerly the Board of Visitors, deals with the prison in South Leicestershire which handles young offenders aged up to 21.
Some are also asylum seekers who have had their requests to stay in the UK rejected.