Omar Khadr's defence team has lost another attempt to have murder and terrorism charges dismissed against the 21-year-old Canadian, but won on another legal matter.

A U.S. military judge Thursday ruled that Khadr's defence team did not prove a top Pentagon official unlawfully interfered in Khadr's case at the U.S. naval base in Guantanamo Bay, Cuba.

But the judge, Army Col. Patrick J. Parrish, also ruled that Air Force Brig-Gen. Thomas Hartmann will be barred from providing counsel during a post-trial review.

Hartmann supervises the chief prosecutor at Guantanamo and has extensive powers over the tribunal system.

The judge said Hartmann has created the appearance that he will be unable to remain neutral and impartial in Khadr's post-trial process because of his "extremely active approach" as legal adviser.

Khadr's military lawyer, Lt.-Cmdr. Commander William Kuebler, characterized the ruling as "token relief."

Khadr is accused of hurling a grenade that killed a U.S. Special Forces commando during a July 2002 firefight at an al-Qaeda compound in Afghanistan. His trial is scheduled for October.