OTTAWA - Four men with detailed accounts of being tortured in Afghanistan and Guantanamo Bay have filed a complaint against Canada with the United Nations over Ottawa's refusal to prosecute former U.S. president George W. Bush.

It is the latest attempt by human rights advocates to arrest the former U.S. leader for alleged crimes perpetrated during the American-led fight against terrorism.

The Canadian Centre for International Justice and the U.S.-based Centre for Constitutional Rights filed the complaint on behalf of Hassan bin Attash, Sami el-Hajj, Muhammed Khan Tumani and Murat Kurnaz.

They maintain Canada should have investigated and prosecuted Bush during his visit to British Columbia last year, in compliance with the UN Convention Against Torture.

The complaint says that in Afghanistan and Guantanamo, the four men experienced inhumane treatment including beatings, being hung from walls or ceilings, denial of sleep, food and water, and exposure to extreme temperatures.

Canada, unlike the United States, is among the countries that allows individuals to file petitions with the UN committee for alleged breaches of the convention.

Justice Department briefing notes on the subject say that while Canada will not become a safe haven for those involved in crimes against humanity, such investigations are complex, lengthy and resource intensive.

"To ensure the most efficient use of resources, Canada prioritizes suspects who reside in Canada," say the notes, prepared for Canada's latest appearance before the UN committee and recently released under the Access to Information Act.

All war crimes cases require the consent of the federal attorney general before charges can be laid, the note adds. "Therefore, from a practical perspective the police consult with the appropriate authorities prior to an individual's arrest."

The note continues that "if pressed" for information on Bush and Cheney, officials should tell the UN committee, "Generally speaking, Canada does not address specific criminal complaints in a public forum."

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