Lawyers for a young Canadian detainee at the U.S. military prison at Guantanamo Bay have sued Canada's prime minister to try to force him to repatriate the terror suspect.

The suit filed in Federal Court Friday argues that Prime Minister Stephen Harper needs to intervene before Toronto-born Omar Khadr stands trial for war crimes before an American military commission in October.

The lawyers say Canada is obliged under international law to ensure Khadr's rehabilitation and social reintegration since he was just 15 when he is alleged to have killed an American medic in Afghanistan in 2002.

The infamous prison, located at an isolated U.S. military base in southeast Cuba, has been widely condemned.