A Navy lawyer has been charged with copying and transmitting secret information about Guantanamo Bay detainees to an unauthorized person.

Lt. Cmdr. Matthew M. Diaz, who was stationed at the U.S. base in Guantanamo Bay for six months, could face more than 36 years in prison if convicted at a military trial of the three charges he faces, Navy Mid-Atlantic Region spokeswoman Beth Baker said.

A charge sheet released Tuesday says Diaz, 40, printed out secret information related to national defense "with intent or reason to believe that the said information was to be used to the injury of the United States or to the advantage of a foreign nation."

The document also says Diaz "did ... wrongfully and dishonorably transmit classified documents to an unauthorized individual."

Baker said that individual — a person outside the government whom she declined to identify — notified federal authorities, prompting the investigation.

The complaint does not specify what type of information Diaz is accused of copying and transmitting, but Baker described it as a document containing names and other identifying information about Guantanamo detainees.

A preliminary hearing likely will be conducted in Norfolk in October, Baker said.

Diaz's civilian attorney, Victor Kelley, did not immediately return a phone message seeking comment.

The incidents allegedly occurred between Dec. 20, 2004, and Feb. 28, 2005. Baker, now stationed in Jacksonville, Fla., worked as a staff judge advocate at Guantanamo Bay from July 2004 until January 2005.

Since 2002, the U.S. military has held foreign nationals suspected of terrorist ties at a detention center at the base in Cuba. Diaz provided counsel to the military command in charge of the detention center, according to the Navy, but was not involved in detainees' cases.

Last spring, the military released the names of hundreds of detainees it was holding at Guantanamo as a result of Freedom of Information Act lawsuits filed by The Associated Press.

Baker said Diaz, who is not in custody and continues to work in Jacksonville, has been in the Navy for 11 years after serving eight years in the Army