Guantanamo detainee called '20th Hijacker' of 9/11 repatriated to Saudi Arabia

A man accused of being the would-be 20th hijacker in the Sept. 11, 2001 attacks has been repatriated to Saudi Arabia after two decades detained at Guantanamo Bay, the U.S. Department of Defense said on Monday.

Mohammad Mani Ahmad al-Qahtani, 46, was transferred to his native Saudi Arabia after a review board determined in June that he no longer represented a significant threat to U.S. national security, the Defense Department said in a written statement.

"The United States appreciates the willingness of Saudi Arabia and other partners to support ongoing U.S. efforts toward a deliberate and thorough process focused on responsibly reducing the detainee population and ultimately closing of the Guantanamo Bay facility," the statement said.

According to a Guantanamo detainee profile maintained by the Defense Department, al-Qahtani was trained by al-Quaeda and sought unsuccessfully to enter the United States on Aug. 4, 2001 to take part in the Sept. 11 attacks.

In all, 38 detainees remain at Guantanamo Bay. Of those, 19 are eligible for transfer, 7 are eligible for a Periodic Review Board, 10 are involved in the military commissions process and two detainees have been convicted in military commissions.