WASHINGTON, Sept 14 (IslamOnline & News Agencies) - A U.S. judge has barred prosecutors at the trial of Zacarias Moussaoui from playing cockpit voice recordings from the hijacked plane that crashed in Pennsylvania on September 11, fearing the tapes could unfairly prejudice the jury.

Moussaoui, a French national of Moroccan descent, has been directly charged with conspiracy in the September 11 strikes and faces the death penalty on four of six federal charges. His trial is due to begin on January 6, 2003.

Federal prosecutors filed a motion to play the tapes to the jury at his trial due to start on January 6.

The tapes appear to have captured the sound of a fierce struggle between the hijackers and a group of passengers who stormed the cockpit of United Flight 93, which was reported to be headed for the White House before crashing in Pennsylvania.

But Judge Leonie Brinkema of Federal U.S. District Court in Alexandria, Virginia, ruled Friday that the tapes appeared "to have marginal evidentiary value while posing unfair prejudice" to Moussaoui.

Moussaoui and Moroccan citizen Mounir El Motassadeq are the only people worldwide to have been charged over the September 11 attacks.

In her ruling, Brinkema ordered the Justice Department to provide a written explanation of the "relevance of these recordings to any issue in dispute and why any probative value outweighs the danger of unfair prejudice."

The U.S. Justice Department has argued that the cockpit tapes "would provide valuable information to the jury about the events that occurred on Flight 93".

But Brinkema ruled that the two black box tapes do not "contain information that is not available to the United States through other evidence," although she deferred making a final ruling to allow the Justice Department to "explain the non-cumulative relevance of these recordings."

On August 8, Brinkema ruled that the prosecution could show videotapes of the attacks, and photos of the more than 3,000 people killed.

Forty-four passengers and crew members were aboard the plane when it crashed into a field in Shanksville, Pennsylvania, killing all on board after what investigators have stated was an attempt by passengers to overpower the hijackers and keep the plane from reaching its alleged destination.