GUANTANAMO BAY, CUBA - Defense attorneys for five suspects facing war crime charges for their roles in the Sept. 11, 2001, terrorist attacks on the United States spent Thursday morning arguing before a military tribunal that their clients' rights have been breeched by unlawful seizures of legal documents from their cells.

The U.S. government concedes that privileged documents were seized from a suspect by guards during a search, but rebuffed suggestions that the search was improper, that the documents were properly marked, or that anyone ever read them.

Navy Cmdr. Walter Ruiz, a defense lawyer for Saudi national Mustafa al Hawsawi, called to the stand military lawyer George Massucco, who serves as the liaison with high-value detainees at Guantanamo Bay, to grill him about the search of Hawsawi's cell.

The search was conducted and the legal documents seized in February, while Hawsawi was appearing in court. They were not returned to Hawsawi until several weeks later.

Throughout the day, Ruiz demanded to know who had seized the documents, who had ordered the search, why they had ordered the search and whether the documents had been reviewed by anyone. The answers proved elusive. Massucco, a lawyer whose proficiency in a courtroom was clear from his elaborate answers, insisted he didn’t know the answers to Ruiz' questions.

Ruiz has strongly suggested that U.S. prosecutors were allowed to review the seized documents, a violation that he said would severely undermine his defense strategy. Ruiz was at times clearly frustrated over what he views as a violation of attorney-client privilege by guards and possibly prosecutors, something he argues would undermine his ability to establish trust with his client and organize a proper defense.

The Pentagon denied defense charges that prosecutors reviewed privileged information taken from the detainees.

"It scarcely requires us to state that the prosecution do not and would not violate the attorney-client privilege," said Lt. Col. Todd Breasseale, a Pentagon spokesman. "The prosecution takes all affirmative measures, as all attorneys are obligated to do, to refrain from viewing privileged material. The defense [has] acknowledged the good faith of the prosecution in this regard."

The day's proceedings continued with a protracted debate between defense lawyers and military officials over the propriety of cell searches and the seizure from detainees of sensitive legal documents intended to aid their defense.

Attorneys for the five men accused of 9/11 war crimes have spent time each morning airing complaints about violation of their clients' rights. One defense attorney complained mail she sent to her client was being seized. Another alleged his client was being purposely subjected to vibrations and noise in his cell while others have complained of a lack of consular access.