Ottawa - A US intelligence agency paid a 500,000-dollar bounty to Pakistan's military for the arrest of the Canadian son of a suspected Al-Qaeda financier, said court documents.

According to an October 2004 memo to the head of the Royal Canadian Mounted Police (RCMP) ordered released by Canada's federal court, Abdullah Khadr was wanted for "supporting insurgent activity in Pakistan and Afghanistan."

Thus, Khadr "is deemed to be a national security threat and has a 500,000 US dollar outstanding bounty for his capture," said the memo published on the website of the daily Globe and Mail, which fought for its disclosure.

Khadr is the eldest son of Egyptian-born Canadian national Ahmed Said Khadr, and the brother of Omar Khadr, the only Canadian held at the US naval base in Guantanamo, Cuba.

He was held in Pakistan for almost a year before returning in 2005 to Canada, where he was arrested and jailed, and is now fighting extradition to the United States.

Justice officials inadvertantly disclosed the top secret memo in court filings last year and fought the Globe and Mail not to publish it, but lost.

Federal Court Judge Richard said in his decision: "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 ... is a matter in which the public would have a legitimate interest."

"The evidence heard in camera supports the conclusion that the bounty was offered and paid by the United States," he added.

Khadr's lawyers maintain that their client was tortured while in Pakistan and his statements to US, Canadian and Pakistani agents are therefore tainted. Khadr attorney Nathan Whitling told the Globe and Mail that Washington was guilty of "outsourcing torture."

"Rather than getting its own hands dirty, the US simply paid the Musharraf regime 500,000 dollars to arrest Mr Khadr, knowing full well what Pakistan would do to him.

"The US then did all it could to hide this secret arrangement from the Canadian judge hearing Mr Khadr's case," Whitling charged.

The RMCP memo says Khadr was also a "primary target" of Canada's anti-terrorism squad "for his role with (Al-Qaeda) training camps."

As well, it says Khadr "is deemed to be a great intelligence asset due to his close relationship" with Al-Qaeda leader Osama bin Laden and other members of the terror network.

Khadr's brother Abdurahman Khadr has admitted on Canadian television that the family knew bin Laden, and that Al-Qaeda operatives trained him and some of his siblings in Afghanistan.

Meanwhile, his brother Omar Khadr faces an upcoming US military tribunal on charges that he murdered a US army medic in Afghanistan in 2002 when he was 15 years old.

Omar Khadr was arrested the same year and has since been held at the US naval base at Guantanamo Bay, Cuba.

The court documents also include a transcript of an RCMP interview in which Khadr says he is not a member of Al-Qaeda, but adds, "I only buy and sell weapons for Al-Qaeda."