Canadian “child soldier” Omar Khadr, who had been a Guantanamo prisoner for a decade, appealed his terror conviction on Friday.
Once the U.S. prison camp's youngest inmate, Khadr returned to Canada in 2012 to serve the rest of his term.
He filed the appeal with the U.S. Court of Military Commissions Review, his Pentagon and Canadian lawyers said.
The motion marked the third time a former Guantanamo prisoner has urged authorities to drop charges of material support for terrorism since late al-Qaeda chief Osama bin Laden's former driver Salim Hamdan saw his conviction reversed in October 2012.
Toronto-born Khadr was 15 years old when U.S. forces detained him in 2002 and accused him of killing a U.S. soldier by throwing a hand grenade during combat in Afghanistan and for planting landmines intended to kill American soldiers.
Khadr’s lawyers said he was abused under U.S. custody and treated as an “adult war criminal.”
They said Khadr was terrorized by barking dogs, threatened with rape, sleep-deprived, held in isolation, restrained in stress positions and physically assaulted.
“The government's decision to treat Khadr as an adult war criminal, rather than a trafficked child soldier, resulted in unjust and unreasonably punitive conditions of confinement.
“Even considering the seriousness of his charges, the punishment inflicted on Khadr since his capture would be atypical for adults in the American justice system, let alone juveniles.”
The brief by Samuel Morison and Dennis Edney also described Khadr's alleged abuse in graphic detail, saying the government “manipulated an injured and vulnerable minor to adopt the preconceived story.”
In one incident, the lawyers said Khadr was used as a “human mop” to wipe the floor after his hands and feet were tied together behind his back for several hours and he urinated on himself as a consequence.
“The guards poured pine solvent on the floor and used Khadr as a human mop, dragging him on his stomach back and forth through the mixture of urine and pine oil,” according to the brief.
“He was returned to his cell and not allowed a change of clothing for two days.”
It said that during one three-month period, Khadr was questioned 20-25 times for up to six hours each session, during which he was often sedated and sleep-deprived.
The filing came just days after another former Guantanamo prisoner, David Hicks of Australia, appealed his war crimes conviction saying he was coerced and that his terror charges were not legitimate war crimes.
“The fact that Khadr and Hicks's guilty pleas came after years of severe abuse and torture by the US military serves as an additional reason why their convictions must now be overturned,” said the Australian's lawyers at the Center for Constitutional Rights.
“Until the military commissions system is scrapped for good, challenges to convictions will plague the Obama administration for years to come.”
Only seven of the 779 people who passed through Guantanamo since the Cuba site opened in 2002 have been sentenced, most due to a guilty plea.