His older brother, Walid bin Attash, remains detained and is a defendant in a military tribunal, accused of helping to plot the September 11, 2001 terrorist attacks on the US.

None of the men in the latest transfer out of the camp had been criminally charged or put on trial during their two decades of detention. All were approved for transfer through federal national security officials.

The men had remained in detention despite being deemed by the US eligible for release for a number of years because they could not legally be returned to Yemen, which remains in the grip of a civil war and deemed by the US to be too unstable to rehabilitate such returnees