A BP PLC well site leader on the Deepwater Horizon is appealing a judge's order he undergo a medical examination before he can claim to be unfit to answer questions under oath about the deadly 2010 rig explosion that spawned the nation's worst offshore oil spill.

Last month, U.S. District Judge Carl Barbier said Donald Vidrine should undergo a medical exam. Vidrine was one of BP's well site leaders on the Deepwater Horizon and he has claimed medical problems should prevent him from being questioned. Rig owner Transocean Ltd. wants to question him.

On Monday, Vidrine appealed Barbier's ruling to the 5th U.S. Circuit Court of Appeals.

A trial over the spill was scheduled to start Monday, but it was delayed indefinitely after a partial settlement was reached.