Lawyers for a Canadian teenager imprisoned in Guantanamo Bay say it's put up or shut up time for the U.S. government, which they further claim has abused Omar Khadr.

"At the end of the day, I want to bring this to an end," Dennis Edney, Canadian lawyer for Omar Khadr, said Wednesday at a news conference.

"It's three years on. You've mistreated this boy for years. Let's see the evidence and let's go to trial."

Omar, now 18, is part of the infamous Khadr family. His later father Ahmed was a known associate of al Qaeda leader Osama bin Laden.

Ahmed died in a 2003 shootout with Pakistani police. Karim Khadr, another of his teenaged sons, was wounded in that incident and left paralyzed. Karim returned to Canada.

Abdullah, an older brother, was accused of running an al Qaeda training camp in Afghanistan. His whereabouts are unknown.

Abdulrahman, another brother, was a fellow Guantanamo detainee. He initially told a story of being returned to Afghanistan, but then claimed he was hired by the CIA to spy on al Qaeda recruiters in Bosnia.

U.S. authorities captured Omar, then 15, in Afghanistan. They declared him an enemy combatant. He is the youngest of an estimated 550 prisoners in Guantanamo, a U.S. enclave on the island of Cuba that has been turned into a prison for so-called "war on terror" suspects.

They accuse him Omar of laying mines aimed at U.S. convoys and of having thrown a hand grenade that killed a U.S. army medic. However, they haven't actually charged him with anything.

Abuse claims

"One of Canada's children has been tortured by the United States," said Muneer Ahmad, a Washington-based lawyer. He visited with Omar for four days in November.

Omar alleged threats of torture, rape and was shackled in painful positions for lengthy periods.

At one point, where he urinated on the floor during an interrogation, Ahmad said guards used him "as a human mop and used his body to clean up the urine."

Omar's mother appeared at Wednesday's news conference and issued this plea through Edney: "As a mother, I beg every Canadian mother and father to help me get justice for my son and bring him home."

Canadian officials say they have been assured by the U.S. that Khadr is being treated humanely.

"Omar is abandoned in a legal black hole beyond the rule of law by a lawless U.S. administration and the Canadian government participates in that violation," Edney said, noting that detainees from other western countries have been released after pressure from their governments.

He further claimed that RCMP, CSIS and Foreign Affairs had participated in Omar's interrogations.

By declaring the Guantanamo detainees enemy combatants instead of prisoners of war, the U.S. believes they aren't subject to the Geneva Conventions.

The U.S. Justice Department is investigating claims of mistreatment that originate in FBI e-mails.

According to a lawsuit launched by the American Civil Liberties Union, the e-mails describe prisoners being chained for up to 24 hours. They also describe prisoners being left in their own feces and urine in rooms that were either extremely hot or cold.

There have been other reports of prisoner abuse, but not as grave as those which occurred at Abu Ghraib prison in Iraq.