Attorneys for millionaire Robert Durst, who faces a California murder charge, say Durst's arrest in New Orleans on weapons charges was invalid, in part because the FBI conducted an unlawful search of his hotel room.

Durst was arrested last month at the J.W. Marriott hotel in New Orleans.

He is set for a Thursday hearing on Louisiana charges of possession of a firearm by a felon and illegally carrying a firearm while in possession of an illegal drug.

Prosecutors say items recovered at the time of his arrest include marijuana and a revolver.

But Durst's lawyers released a court filing Wednesday that says Durst's arrest documents are invalid because they cover up the fact that FBI agents searched the room before police obtained a warrant.