Pentagon officials also said they were looking into newly public allegations that interrogators at the U.S. military prison at Guantanamo questioned detainees under the guise of being FBI agents.
The American Civil Liberties Union obtained and released e-mails that showed FBI officials disapproved of the practice and suggested the military interrogators were trying to take advantage of the rapport the FBI had established with some detainees.
Pentagon spokesman Bryan Whitman said such a technique was not on a list of interrogation methods approved by Defense Secretary Donald Rumsfeld. It was difficult to determine from the e-mails, however, whether it "was permissible or not." Defense officials said it is permissible to impersonate a foreign national during interrogations.
The military operation at Guantanamo Bay has come under increased scrutiny as former prisoners have alleged they were tortured. The Pentagon maintains it runs a humane operation there, and says all allegations of abuse are investigated.
Asked about Guantanamo at his news conference Monday, President Bush said, "You've got to understand the dilemma we're in. These are people that got scooped up off a battlefield attempting to kill U.S. troops. And I want to make sure, before they're released, that they don't come back to kill again."
Of the roughly 200 that have been released at least a dozen have returned to the battlefield, Navy Secretary Gordon England said.
The newest prisoner to face release would be the second to be freed under a military process instituted to help satisfy the Supreme Court's ruling during the summer that prisoners at Guantanamo could challenge their detentions through the U.S. court system.
To bolster its case for each of the prisoners against any such challenge, the Pentagon set up tribunals to review circumstances of each man's capture and other factors to determine whether they are properly held.
England refused to provide the name or nationality of the prisoner to be released, and the circumstances of his capture were not immediately available. The State Department has been notified of the decision and will arrange to return him home.
For 228 other prisoners at Guantanamo, a panel of three military officials determined they were properly held. In the tribunals, formally called Combatant Status Review Tribunals, a three-person panel studies a prisoner's case and forwards its findings to the officer who convened the tribunals for a final ruling.
More than 300 additional cases are still being reviewed.
The ACLU's latest releases about the prisoners' treatment were obtained through the Freedom of Information Act and primarily constitute e-mails between FBI officials whose names were removed by the government before they were released. In several, the writers describe and criticize various interrogation techniques they say they witnessed at Guantanamo.
While military interrogators are performing much of the questioning at Guantanamo, the FBI and CIA also have operations there.
In one, the writer describes seeing a "detainee sitting on the floor of the interview room with an Israeli flag draped around him, loud music being played and a strobe light flashing." Another Guantanamo prisoner has, in a court petition, described detainees wrapped in Israeli flags, among other allegations. At the time, a Guantanamo Bay spokesman denied his statements.
Anthony Romero, executive director of the ACLU, say the latest release of FBI documents continue to show the U.S. government was "torturing individuals in some instances" and demonstrates a major rift between FBI agents and the military over proper interrogation techniques.
"There was real concern within our law enforcement community about whether we are torturing individuals," Romero said.
One FBI e-mail dated May 22, 2004, suggested President Bush personally signed off on various harsher interrogation techniques in an executive order.
However, "What the FBI agent wrote in the e-mail is wrong. There is no executive order on interrogation techniques," White House press secretary Scott McClellan said Monday. "Interrogation methods for military detainees are decisions made by the Department of Defense."
The FBI would not comment on the release of documents.
Also Monday, a federal judge in New York said he planned to deny a request from the government to delay a review of whether certain CIA internal files related to Iraq should be made public.
The comments from Judge Alvin Hellerstein was a victory for the ACLU and other groups seeking information about the treatment of detainees at Guantanamo and Iraq.
By John J. Lumpkin