WASHINGTON (AP) — The Air Force translator accused of espionage at the prison camp for terror suspects was under investigation before he arrived at the Guantanamo Bay base, a military investigator says.

The Air Force Office of Special Investigations began looking into the case of Senior Airman Ahmad I. al-Halabi in November 2002 while he was a supply clerk at Travis Air Force Base in California, the agent wrote in court documents. Al-Halabi was sent to the Cuban base weeks later as an Arabic language interpreter for the al-Qaida and Taliban suspects there.

Al-Halabi, 24, now is charged with espionage for allegedly e-mailing classified information about the prison camp to an unspecified "enemy" and planning to give other secrets about the prison to someone traveling to Syria. He is one of two military members at the prison camp to be arrested during an investigation of possible security breaches there.

The other suspect, Army Capt. Yousef Yee, a Muslim chaplain, is being held without charge at the Navy brig in Charleston, S.C. Al-Halabi is behind bars at Vandenberg Air Force Base, Calif., forbidden to speak Arabic.

The military has tightened security at Guantanamo Bay since the arrests, with officials making sure that restrictions on handling documents, making phone calls and sending e-mails are being followed, said Army Lt. Col. Pamela Hart, a base spokeswoman.

OSI Special Agent Lance R. Wega asked a federal court in Sacramento, Calif., for a warrant to collect a package al-Halabi sent from Guantanamo Bay to his home address at Travis Air Force Base. Federal magistrate Gregory G. Hollows granted the search warrant on Sept. 5.

An Air Force spokesman, Lt. Col. Rob Koon, said Thursday he had no information on why al-Halabi was allowed to work at Guantanamo Bay when he had been under suspicion before arriving at the prison camp.

Al-Halabi says he is innocent. One of his lawyers, Air Force Maj. James Key III, said al-Halabi is a naturalized U.S. citizen and a patriotic American.

The most serious of the 32 charges against al-Halabi carries a possible death sentence. Brig. Gen. Bradley S. Baker, the commander of al-Halabi's unit, has not decided whether al-Halabi will be tried by court-martial or, if he is convicted, face a possible death sentence.

While at Guantanamo Bay, al-Halabi "made statements criticizing United States policy with regard to the detainees and U.S. foreign policy in the Middle East," Wega wrote. The agent wrote that al-Halabi also "expressed sympathy for and has had unauthorized contact with the detainees."

The charges against al-Halabi include an accusation that he lied to investigators when he denied making anti-American statements. Al-Halabi also is charged with violating military orders by having improper contact with the prisoners.

Military investigators made a secret search of al-Halabi's quarters at Guantanamo Bay on July 19, five days before he was arrested in Florida on his way back to California, Wega said.

The investigators found several pieces of mail belonging to al-Qaida and Taliban suspects at the prison camp, Wega stated. They took pictures of the letters and made a copy of the hard drive of al-Halabi's computer and left.

On that hard drive, agents found about 186 classified Defense Department documents related to the detainees at Guantanamo Bay, according to Wega, who said those documents were found on his laptop computer hard drive when al-Halabi was arrested.

Computer evidence indicates al-Halabi e-mailed or posted to the World Wide Web four of those documents, the special agent alleged.

The implication is that al-Halabi was helping the prisoners communicate among themselves and with the outside world. Military officials will try to determine whether the messages from the prisoners would have damaged the war on terrorism and whether the inmates are trying to organize resistance to their interrogations.

Before he left Guantanamo Bay, al-Halabi mailed a Dell computer box to himself that investigators believe contained other classified information, Wega alleged. The agent sought a search warrant for the post office at Travis Air Force Base to seize that package and a letter to al-Halabi from the Syrian Embassy.

Al-Halabi also is charged with failing to report improper contact with the Syrian Embassy. Syrian officials deny al-Halabi was a Syrian spy or passed any classified information to the government in Damascus.

Key said al-Halabi had planned to fly to Syria in late July to get married. Al-Halabi's contacts with the Syrian Embassy were related to that trip and his efforts to make sure his new wife could return to the United States with him, Key said.