WASHINGTON, September 21 (IslamOnline & News Agencies) - A Muslim U.S. Army chaplain who counseled the 660 detainees held by the U.S. in Guantanamo Bay, Cuba, has been detained on charges of possessing classified documents about the detainees and their interrogators, according to U.S. officials.

Capt. Thomas Crosson, a spokesman for the U.S. Southern Command, the Florida-based military unit overseeing the Navy base at Guantanamo Bay, said Captain James Yee, who has changed his name to Youssef his accepting Islam in 1990, had been in military custody since September 10.

He said Youssef, a West Point Military Academy graduate, had been "detained" but "no formal charges, either criminal or civil," have been filed against him, reported the Washington Post Sunday, September 21.

Crosson said the man Youssef was being interrogated at the U.S. Navy detention facility in Charleston, South Carolina.

Suspected al-Qaeda operatives Jose Padilla and Yaser Esam Hamdi have been held and questioned at the same facility, reported Agence France-Presse (AFP).

Youssef was arrested at Jacksonville Naval Air Station in Florida as he stepped off a military plane that brought him from the Guantanamo on rest and recuperation leave.

According to the Post, "FBI and military investigators are trying to determine whether (Youssef) has revealed to other people any of the sensitive information from the files he had."

The BBC News Online said the documents included maps detailing the location of various prisoners within the Camp Delta detention and the names of their interrogators.

Youssef had been assigned to counsel the detainees in Cuba starting 10 months ago and before that he was a Muslim chaplain at the Army's Fort Lewis in Washington state.

In an interview with the BBC earlier this year, he said he was sent to Guantanamo to help those being held at the base.

"I like to think that whatever I can do, whether in their personal situation or help with them being here in any way, that I have a positive effect on their life."

A Chinese-American, Youssef grew up a Lutheran in a New Jersey suburb, graduated from West Point in 1990 and then commanded a Patriot missile battery.

He converted to Islam about the time he served in Saudi Arabia after the Gulf War.

After quitting the military, he spent four years studying Islam in Damascus, Syria, before returning to the U.S. as a trained imam.

Following the September 11 attacks, Youssef became active on the media circuit, giving interviews about the peaceful nature of Islam and condemning the strikes.

"Islam comes from a word, which means peace," he told Voice of America radio in October 2001.

"So when people like to characterize Islam as being violent, again they are harping off what they see on television, what they see in the movies, without studying about Islam from the traditional sources of Islam, the Koran, and the prophetic traditions of the prophet Mohammed and the sources of Islam."

"An act of terrorism, the taking of innocent civilian lives, is prohibited by Islam, and whoever has done this needs to be brought to justice, whether he is Muslim or not," Yee said at the time.

Ibrahim Hooper, a spokesman for the Council on American-Islamic Relations, told the New York Times he was concerned Youssef’s arrest would provoke ill-feeling.

"There are those in our society who love to question the patriotism of American Islamics and this unfortunately will give them ammunition to do that, no matter what the facts of the case are," he said.

According to the Washington Post Yee's detention is only the latest controversy to hit the chaplain program, which oversees the approximately 12 Islamic imams in the U.S. military.

"The inspectors general for the Pentagon and the Justice Department have launched reviews of the Muslim chaplain programs in the U.S. military and in federal prisons."

Most of the Guantanamo prisoners, who come from more than 40 countries, were captured by U.S. forces in Afghanistan and include, according to U.S. officials, al-Qaeda and Taliban members.

They have been held and interrogated by the United States there for up to 18 months. None of them have been charged with any crime.

Classified as "illegal combatants" by President George W. Bush, their fate is uncertain.