Federal Court Justice Richard Mosley issued a decision that the information, which Khadr wants to use to fight his extradition to the United States from Canada, can be publicly disclosed.
Khadr was arrested in Pakistan in 2004 and sent back to Canada in 2005. Canada detained him in December 2005 and since February 2006 the United States has sought his extradition on charges that he sold rockets and other weapons to al Qaeda and conspired to kill Americans in Afghanistan.
Khadr says he was tortured and detained illegally in Pakistan and statements he gave should be excluded, according to the reports.
"He seeks to corroborate his allegations that agents of the United States were behind his capture and detention in Pakistan and complicit in any abuse that he suffered during his detention there," Mosley said.
Abdullah Khadr is the eldest son of Ahmed Said Khadr, a friend of al Qaeda leader Osama bin Laden and alleged al Qaeda financier, who was killed in a 2003 gun battle in Pakistan.
Abdullah Khadr's brother, Omar, is the only Canadian prisoner being held at the U.S. detention camp for terrorism suspect in Guantanamo Bay, Cuba. The Canadian government is facing increasing domestic and international calls to press the U.S. government for his release.
The United States government's bounty programme has been well publicized. It began in the 1980s and was strengthened after the September 11 attacks in 2001.
"The general practice is in the public domain," Mosley said in justifying his decision to release the news. He said it was clear that Canadian officials had been told that a bounty had been paid after Abdullah Khadr's capture.
"The fact that a foreign state paid a bounty for the apprehension of a Canadian citizen abroad and that Canadian officials were aware of it at an early stage is also a matter in which the public would have legitimate interest," Mosley wrote.