(AP) A federal judge on Thursday barred the government from seeking the death penalty for terrorism suspect Zacarias Moussaoui, inflicting a major defeat on the government for refusing to let the defendant question three al Qaeda prisoners.

U.S. District Judge Leonie Brinkema rejected a more severe option to dismiss all charges. The government had acknowledged dismissal would be appropriate, so there could be a quick appeal of her earlier ruling grantings Moussaoui access to the prisoners.

She said the government's notice of intent to seek a sentence of death must be stricken and prosecutors cannot present any evidence or argument that the defendant was involved in, or had knowledge of, planning the Sept. 11 attacks.

Brinkema postponed the effect of her ruling so the government could appeal.

The government had been anticipating a dismissal, telling Brinkema that throwing out the charges would be the quickest route to intervention by an appellate court. Moussaoui and his court-appointed defense team had asked for dismissal.

Brinkema was responding to government defiance of her rulings in January and August, which granted Moussaoui access to the prisoners through a satellite connection.

Brinkema concluded that Moussaoui's constitutional right to potentially favorable witnesses took precedence over the government's need to protect classified information that could be revealed in testimony by the captives.

Prosecutors had argued that national security would be gravely harmed if any details were revealed about the sensitive interrogations of the prisoners, who are held in undisclosed locations outside the United States.

The Bush administration could decide to move Moussaoui's case to a military tribunal, where national security would likely trump a defendant's access to witnesses. However, that decision would likely be made only after the 4th U.S. Circuit Court of Appeals, in Richmond, Va. ruled on the witness-access issue. The side that loses in the appellate court could ask the Supreme Court to intervene.

Two of the prisoners were among Osama bin Laden's top operatives, Sept. 11 mastermind Khalid Shaikh Mohammed and a key planner of the attacks, Ramzi Binalshibh. The third is Mustafa Ahmed al-Hawsawi, a suspected paymaster for al Qaeda.

Prosecutors argued that interrupting their interrogations would be a sensitive matter for the United States, because intelligence officials are learning valuable information about al Qaeda's operations.

Mohammed, for instance, told U.S. officials the Sept. 11 plot was five years in the making and that a wave of suicide attacks was supposed to follow, The Associated Press reported after reviewing interrogation reports.