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

A man accused of being the would-be 20th hijacker in the 11 September, 2001 attacks has been repatriated to Saudi Arabia after two decades detained at Guantanamo Bay, the US Department of Defence 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 US national security, the Defence Department said in a written statement.

"The United States appreciates the willingness of Saudi Arabia and other partners to support ongoing US 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 Defence Department, al-Qahtani was trained by al-Qaeda and sought unsuccessfully to enter the United States on 4 August 2001 to take part in the 11 September attacks.

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