The Justice Department on Monday defied a judge's order and blocked terrorism suspect Zacarias Moussaoui (search) from questioning suspected Sept. 11 organizer Ramzi Binalshibh (search) by failing to produce the witness.

The bold move by the government could lead to dismissal of the case, and ultimately to prosecution in a military tribunal.

U.S. District Judge Leonie Brinkema (search) could also respond by barring government evidence, throwing out some charges or instructing jurors that the government refused to provide certain evidence in the only U.S. case to arise from the 2001 attacks.

• Raw Data: The Government's Position (Findlaw PDF)

The department's move is likely to trigger intervention by the 4th U.S. Circuit Court of Appeals in Richmond, Va., but not immediately. The full court voted 7-5 on Monday to deny, for now, reconsideration of a three-judge panel's refusal to step in at this stage.

While the appellate ruling was only procedural at this point, chief Judge William Wilkins warned that the court would not blindly accept government claims of national security in the refusal to produce Binalshibh.

"Siding with the government in all cases where national security concerns are asserted would entail surrender of the independence of the judicial branch and abandonment of our sworn commitment to uphold the rule of law," Wilkins said.

The government said it recognizes that its objection means the deposition of Binalshibh cannot go forward, and that the decision "obligates the court now to dismiss the indictment unless the court finds that the interests of justice can be served by another action."

If the court considers an alternative to dismissal, prosecutors asked that they be heard before action is taken. The government also asked Brinkema to postpone any action pending a ruling by the appellate court.

Brinkema has ruled that Moussaoui, who is representing himself, should be allowed to question Binalshibh through a satellite hookup. The exchange, which the government is desperately trying to stop, could be played to jurors if Moussaoui's case goes to trial.

Brinkema had concluded Binalshibh may support Moussaoui's contention that he was not part of the Sept. 11 conspiracy.

Attorney General John Ashcroft (searchhas repeatedly said he wants to continue the prosecution in the civilian court system, although military tribunal rules would make national security paramount over Moussaoui's constitutional right to have access to a potentially favorable witness.

"The military commission approach is outside the constitutional system," said Robert Precht, assistant dean for public service at the University of Michigan law school and a defense lawyer in the 1993 World Trade Center bombing (searchcase.

"Once you take this out of the civilian system, all bets are off. All constitutional rights that are familiar to us are simply not applicable. What limited rights the military does give are totally at the government's mercy."

The eventual outcome of this dispute could affect future cases by deciding whether terrorism defendants will have access to enemy combatants, especially those, like Binalshibh, who are being held in secret locations overseas.

Should the civilian courts favor a defendant's access to potential witnesses over national security, the government could decide that future terrorism proceedings should be prosecuted by military tribunals.

Repeating earlier arguments, the government said Monday: "The deposition, which would involve an admitted and unrepentant terrorist (the defendant) questioning one of his Al Qaeda confederates, would necessarily result in the unauthorized disclose of classified information.

"Such a scenario is unacceptable to the government, which not only carries the responsibility for prosecuting the defendant, but also of protecting this nation's security at a time of war with an enemy who already murdered thousands of our citizens."

Moussaoui has admitted he's an Al Qaeda loyalist, but denied he was part of the Sept. 11 plot.

The Associated Press contributed to this report.