NEW YORK -- Osama bin Laden's son-in-law says he was tortured by the U.S. and is asking a New York judge to dismiss the terrorism case against him.

Lawyers for Sulaiman Abu Ghaith filed papers Friday in Manhattan federal court.

Abu Ghaith has been held without bail since he was brought to the United States in March to face charges he conspired to kill Americans. Prosecutors say he carried out the conspiracy in his role as al-Qaida's spokesman after the Sept. 11 attacks.

His lawyers say he was tortured in U.S. custody during a 14-hour flight from Jordan. They also say the indictment violated their client's due process rights and failed to specifically describe his role in a conspiracy.

Prosecutors declined to comment on the defence motion.