Home Secretary Theresa May has ordered a review of border officials' handling of asylum claims made by gay and lesbian applicants following reports that some claimants had handed over video evidence to prove their sexuality.
MPs have previously raised concerns that the process for lesbian and gay applicants, many of whom are fleeing persecution in their home countries, relied too heavily on anecdotal evidence and ''proving that they are gay''.
And a Home Office document leaked earlier this year revealed how one bisexual asylum seeker was asked a series of questions including: "Did you put your penis into x's backside?" and "When x was penetrating you, did you have an erection?"
As a result, the Home Secretary has asked the Independent Chief Inspector of Borders and Immigration, John Vine, to review asylum claims made on grounds of sexual orientation.
In a letter to Mr Vine, Mrs May said: "We do need to establish that the risk of persecution is real, and this will often depend on whether the sexual orientation of the asylum seeker is as claimed.
"We seek to establish this at interview through questions about sexual orientation, not sexual behaviour.
"It was disappointing therefore to discover that we may not have followed our guidance in at least one case, which was brought to the attention of the media recently and where inappropriate questions appear to have been asked.
"We are committed to treating all asylum claimants with respect and dignity and we want to continue to improve on current practice in this area."
Mr Vine has been asked to look at the adequacy of guidance for staff and claimants, training, whether guidance and training is being followed by looking at a sample of case files.
The leaked Home Office document revealed that during five hours of questioning in a UK detention centre, a male asylum seeker was also asked: "What is it about men's backsides that attracts you?" and "What is it about the way men walk that turns you on?"
The questions, typed up by a Home Office employee, and dated last October, were branded an "interrogation".