Syria has angrily rejected American allegations linking it to a US serviceman accused of spying at the Guantanamo Bay detention camp in Cuba.
Mr Halabi worked as a translator at the base
Senior Airman Ahmad al-Halabi, 24, who is of Syrian origin, worked as a translator at the US base, where hundreds of suspected members of Al-Qaeda and the Taleban are being held without charge.
He faces 32 charges, including helping the enemy, and is accused of contacting Syrian diplomats.
The Syrian information minister Ahmad al-Hassan called the allegations baseless and illogical, and said it was incredible that a translator in such a position would not have undergone intelligence screening.
"How could Syria have spies in Guantanamo? Is the CIA incapable of finding a trustworthy translator?" news agency AFP quoted him as saying.
Last week, an American army Muslim chaplain at Guantanamo Bay was arrested on suspicion of spying.
The US Defence Department is not saying whether the latest case is linked to the chaplain, Captain Youssef Yee.
Investigations into security breaches at the base were continuing and there could be further arrests, officials say.
The most serious charges al-Halabi faces - of espionage and aiding the enemy potentially - carry the death penalty, but officials say no decision has even been made yet on a trial.
A military attorney representing Mr Halabi has denied the charges, telling the Washington Post newspaper: "Airman al-Halabi is not a spy and he is not a terrorist."
The US Air Force has said Mr Halabi's arrest and a preliminary hearing was kept secret "to protect ongoing
Given the sensitivity surrounding the Guantanamo base, any link between the two is bound to be a focus for investigators, as well as whether any potential breach in security goes even further, says the BBC's Pentagon correspondent Nick Childs.
Mr Yee, formerly known as James Lee, worked as a spiritual adviser to the hundreds of captured al-Qaeda and Taleban suspects at the base.
Unofficial reports said the Federal Bureau of Investigation had taken classified documents from Mr Yee, as well as a map detailing the location of individual prisoners.
The military has 120 days to complete an investigation and determine whether Mr Yee might face formal charges and a possible military court martial, a military spokesman told Reuters news agency.