A British transsexual is suing United Airlines claiming he was ordered to get off a plane and change into men's clothing before re-boarding.
Richard Ward, also known as Sarah West, was on a flight from Omaha, Nebraska, to Chicago, where he was scheduled to take a connecting flight home to London.
When he showed United staff his British passport, identifying him as a man, he was told to get off the plane and change into men's clothing, claims the lawsuit filed in Cook County Circuit Court.
He says he showed United staff a letter from his doctor that explained it was normal for him to dress as a woman because he was undergoing treatment for "male-to-female transsexualism".
But the transsexual claims he was told he would not be allowed to fly until he looked more like his passport photo.
United spokesman Andy Plews said he could not comment specifically because he had not seen the lawsuit.
"United's record on diversity speaks for itself," Mr Plews told a Chicago newspaper. "We were named one of Fortune's top 50 companies on diversity."
The lawsuit is seeking damages of more than $50,000 (about £35,000).