A US airman who worked as a translator at the Guantanamo Bay camp for suspected terrorists has been charged with espionage and aiding the enemy.
Senior airman Ahmad al-Halabi is being held at Vandenberg Air Force Base in California, spokesman Major Michael Shavers said.
Mr Al-Halabi worked as an Arabic language translator at the prison camp for al Qaida and Taliban suspects, Shavers said.
He knew the Muslim chaplain at the prison arrested earlier this month, but it is unclear if the two arrests are linked, Shavers said.
Mr Al-Halabi is charged with nine counts related to espionage, three counts of aiding the enemy, 11 counts of disobeying a lawful order, and nine counts of making a false official statement.
He was based at Travis Air Force Base in California and assigned to a logistics unit there.
Pentagon officials said an investigation into possible security breaches at Guantanamo Bay continues.
The military has classified many details about the prison camp and the detainees.
The Muslim military chaplain who ministered to the inmates at the camp, Army Captain Yousef Yee, was arrested on September 10 in Jacksonville, Florida, after getting off a flight from Guantanamo Bay.