Updated

A veteran FBI agent is defending his Guantanamo Bay interrogation of a suspect in the Sept. 11 terrorist attacks.

Special Agent James Fitzgerald says in a pretrial hearing that Saudi prisoner Mustafa al-Hawsawi was told the questioning was voluntary. He says the prisoner had a "friendly, reserved demeanor" when he was questioned back in 2007.

Fitzgerald was part of a counter-terrorism team brought to Guantanamo to get statements from al-Hawsawi and other prisoners suspected of involvement in the Sept. 11 terrorist attacks.

But a defense lawyers is raising questions about those interrogations, including whether it was appropriate to question al-Hawsawi in English when Arabic is his first language.

Fitzgerald was the first witness Monday in a weeklong pretrial hearing for five prisoners charged in the attacks.