United Airlines has opened an investigation into the report that a giant rabbit, bred to be the world's largest, died on one of its trans-Atlantic flights.

Distraught breeder Annette Edwards from Worcestershire in central England told The Associated Press by phone Wednesday that Simon, a 10-month-old, 3-foot-long continental rabbit, had a vet check shortly before traveling from London's Heathrow airport to Chicago's O'Hare airport. She said Simon had been purchased by a celebrity whom she did not identify.

"Simon had his vet check just before getting on the plane," she said. "He was fit as a fiddle."

The airline said in a statement that it was "saddened" by the news and had been in contact with Edwards and offered assistance. The company is still reeling from a public relations disaster after a passenger who would not give up his seat was dragged forcibly from a plane in Chicago three weeks ago.