Omar Khadr's lawyers will press to have prosecution evidence thrown out as the latest chapter in the Canadian citizen's long-running saga in Guantanamo Bay begins this week.
His American lawyers, Barry Coburn and Kobie Flowers, plan to argue in a pre-trial motion starting Wednesday that Mr. Khadr gave self-incriminating statements only after horrendous mistreatment by his American captors.
"He was abused, and therefore the statements are unreliable," said Nate Whitling, one of Khadr's Canadian lawyers.
"They have nothing else."
Mr. Khadr was 15 years old and horribly wounded when captured in the rubble of a compound in Afghanistan in July 2002 following a four-hour firefight with American forces.
Several others in the compound were killed.
At the tail end of the incident, someone threw a hand grenade that killed a U.S. soldier and blinded another.
Prosecutors maintain the thrower was Mr. Khadr - charged with murder in violation of the rules of war - although at least one witness has indicated someone else might have tossed the explosive.
Among hundreds of statements Mr. Khadr gave both as a prisoner at Bagram Air Base and later at Guantanamo Bay was at least one in which he described throwing the grenade.
At other times, Mr. Khadr denies involvement or says he made the admission only because he had been tortured.
The prosecution, led by Maj. Jeffrey Groharing, has branded the defence claims as a "baseless" tactic.
"The admissions of the accused to numerous trained government investigators are not the product of, or procured by, any torture, coercion, or cruel, inhumane or degrading treatment," the prosecution states in written materials.
"The uncorroborated assertions of the accused to the contrary are false and self-serving."
Even if some of the statements were coerced, Mr. Groharing argues, they should still be admissible.
Evidence about Mr. Khadr's mistreatment that has previously emerged includes sleep deprivation and being held in stress positions.
The pre-trial hearing before Col. Patrick Parrish comes about 16 months after U.S. President Barack Obama called a halt to the military-commission proceedings and promised to shut down the infamous prison.
However, the prison remains and the commissions - condemned both within the U.S. and internationally - are continuing.
"It turned out to be just another delay," Mr. Whitling said.
The prosecution also wants to use a videotape showing the teenaged Mr. Khadr working on an improvised explosive device.
The defence maintains the video was found in the rubble of the compound based on information extracted from Mr. Khadr under torture at Bagram.
Mr. Khadr, now 23, was transferred to Guantanamo Bay in October 2002 and has remained in detention there ever since.
Prime Minister Stephen Harper has refused all calls from Mr. Khadr's lawyers, the political opposition, and legal, human-rights and church groups to press the United States for his repatriation.
In January, the Supreme Court of Canada found Canadian agents had violated Mr. Khadr's rights by interrogating him at Guantanamo. The government responded by asking Washington to ignore any statements he gave to them.
Mr. Khadr's trial is expected to start in late July.
Mr. Khadr's oldest brother, Abdullah, remains in detention in Toronto pending a decision on whether he should be extradited to the United States to stand trial on terrorism-related charges.