The U.S. military justice system at Guantanamo Bay, Cuba, which has been dogged by charges of secret monitoring of proceedings and defense communications, became embroiled in a fresh controversy Thursday when it was revealed that hundreds of thousands of defense emails were turned over to the prosecution.

The breach prompted Col. Karen Mayberry, the chief military defense counsel, to order all defense lawyers with cases at Guantanamo to stop using Defense Department computer networks to transmit privileged or confidential information until the security of such communications is assured.

Army Col. James Pohl, the chief judge at Guantanamo, also ordered a two-month delay in pretrial proceedings in the military commission case against Abd al-Rahim al-Nashiri, who is accused of organizing the 2000 bombing of the USS Cole in Yemen. Defense attorneys in the trial of Khalid Sheik Mohammed, the professed mastermind of the Sept. 11, 2001, attacks, and four codefendants filed an emergency motion — via a handwritten note — seeking a similar pause in proceedings.