An officer at an immigration detention centre in Bedfordshire has been suspended over an allegation he had a relationship with a detainee.
The man, employed by Serco, worked at the Yarl's Wood Removal Centre near Bedford and was suspended in January.
Serco said a staff member was suspended and faced internal and professional standards investigations.
The Home Office said two people had been suspended over separate allegations but one was back at work.
One has since returned to duty while the other remains suspended pending the outcome of an investigation.
Immigration minister Damian Green said: "The UK Border Agency expects the highest standards of behaviour from its staff and contractors.
"When an officer is found to have acted inappropriately, he or she will face sanctions."
Serco took over the running of Yarl's Wood Immigration Removal Centre in April 2007.
The centre, opened in November 2001, had been hit by a series of incidents, including a major fire in February 2002 which destroyed half the building.
Mr Green was answering a written parliamentary question from Labour MP Bridget Phillipson who represents Houghton and Sunderland South.