The evidence for any such listening, the subject of a hearing that started Monday at this U.S. base in Cuba, is circumstantial.
At a hearing Jan. 28, the sound system in the Guantanamo courtroom was suddenly cut, to the surprise of even the judge. The judge later revealed that a government official, from an agency that the military has refused to disclose, was following the proceedings from outside the courtroom and intervened to prevent the potential release of classified information.
The judge, Army Col. James Pohl, later said the information was not classified and he ordered the undisclosed government agency to disconnect any equipment that could unilaterally cut the sound. He also released a transcript of the censored remarks.
But since the Jan. 28 incident, lawyers for the defendants say they have become more concerned about possible additional monitoring that they say would violate attorney-client privilege and make it impossible for them to represent men charged with aiding and planning the Sept. 11 attacks. They have asked the judge to halt all proceedings until the issue is resolved.
"What happened in the courtroom (on Jan. 28) was shocking," said Army Capt.
One concern is the audio system inside the high-tech courtroom overlooking Guantanamo Bay. The microphones at each defense table are so sensitive that officials are apparently capable of hearing even whispered conversations between the defense lawyers and their clients, attorney James Connell said. Other lawyers said they are also worried about possible monitoring of their conversations in rooms where they meet with the defendants.
The chief prosecutor, Army Brig. Gen. Mark Martins, said there is no evidence of any monitoring.
"My staff and I spent a full week diligently running every rumor to ground, and I can say unequivocally that no entity of the United States government is listening to, monitoring or recording communications between the five accused and their counsel at any location," Martins said before the start of Monday's hearing.
Martins, without conceding there had been any monitoring, later offered a partial solution: He said the microphones inside the courtroom could be altered so that they would only be live when activated by the attorneys, making them less likely to pick up a stray comment.
It was not enough, however, to resolve the issue. David Nevin, Mohammed's civilian attorney, asked for an additional day to gather information and interview witnesses. The judge seemed to be skeptical that the defense had any evidence of eavesdropping but he agreed to the delay and adjourned the hearing until Tuesday after just over an hour of discussion.
Mohammed, the self-professed mastermind of the Sept. 11 attacks, and the four other defendants are being tried by a military commission, which is a special tribunal for wartime offenses that includes elements of a court martial and a civilian court. They face charges that include nearly 3,000 counts of murder and terrorism for their alleged roles planning and aiding the 2001 terrorist attacks and could get the death penalty if convicted.
Proceedings are being held in a specially built courtroom in which the spectators, including journalists, observers from human rights groups and relatives of people killed in the Sept. 11 attacks, watch from being sound-proof glass and hear an audio feed that goes through a 40-second delay so a security official inside the court can cut the sound if any classified material is said out loud.
The chief prosecutor says the use of a 40-second delay is necessary to protect information such as intelligence sources and methods that have been legitimately classified to protect national security. Defense lawyers and other critics of the proceedings say the government is seeking to cover up details about the harsh treatment of defendants that amounted to torture.