The Trudeau government is poised to offer an apology and a $10-million compensation package to former child soldier Omar Khadr for abuses he suffered while detained in the U.S. military prison for captured and suspected terrorists at Guantanamo Bay, Cuba.

The Supreme Court of Canada ruled in 2010 that the actions of federal officials who participated in U.S. interrogations of Mr. Khadr had offended "the most basic Canadian standards about the treatment of detained youth suspects."

The court said the action of the Canadian government had violated the former child soldier's rights under the Charter of Rights and Freedoms and deprived him of fundamental principles of justice.

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Read more: How can Canada condone torture?

A federal insider said the announcement of an official apology and compensation is expected this week.

Mr. Khadr's lawyer, Dennis Edney, has been seeking a formal apology from the United States and from the Trudeau government for the alleged abuse and neglect of Mr. Khadr while he was in the prison. Attempts to reach Mr. Edney for comment on Monday were unsuccessful.

The apology and compensation is similar to the $10.5-million that Ottawa gave Syrian-born Canadian Maher Arar after a 2006 judicial inquiry found Canadian officials had passed on information about him to U.S. national-security authorities, leading to his torture and imprisonment in Syria.

Mr. Khadr was captured in Afghanistan at the age of 15 in 2002, following a shootout with U.S. troops where he was badly wounded – blinded by shrapnel in one eye and with fist-sized exit wounds in his shoulder and chest.

He was accused of throwing a grenade that killed U.S. army medic Christopher Speer in the firefight and was sent to the U.S. detention facility in Guantanamo Bay.

Mr. Khadr, now 30, spent more than 10 years in U.S. and Canadian custody, much of that time in the Guantanamo Bay detention centre. Once the youngest detainee in Guantanamo, he was transferred to Canada in 2012 after accepting a plea deal.

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Mr. Edney has said his client was treated abysmally even though he was a child soldier and his body shattered from wounds. U.S. interrogators subjected him to sleep deprivation and solitary confinement.

Mr. Edney said Mr. Khadr was coerced into fighting by his father, Ahmed Said Khadr – a top al-Qaeda operative until he was killed in a gunfight with Pakistani troops in 2003.

In March, Mr. Khadr underwent a 19-hour operation in an Edmonton hospital to repair his shoulder, which was severely damaged during the firefight with U.S soldiers.

"Nobody advocated for his health whatsoever. Even when he came back to Canada, I raised all those issues with the Correctional Services and of course [former prime minister Stephen] Harper was not interested in hearing anything like that," Mr. Edney said in an interview last March.

Mr. Khadr was freed on bail in May, 2015, and released under the supervision of Mr. Edney.

He said he would "prove to [Canadians] that I'm a good person."

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The International Civil Liberties Monitoring Group and Lawyer's Rights Watch Canada have concluded that Canada contravened its obligations under the Conventions against Torture by failing to prevent and investigate what happened to Mr. Khadr in Guantanamo Bay.

Last March, Public Safety Minister Ralph Goodale issued an apology and compensation package to three Muslim Canadian men – Abdullah Almalki, Ahmad Abou-Elmatti and Muayyed Nureddin. They had been tortured and held for months in Syria and Egypt, suspected of links to terrorism.

A decade ago, they each filed $100-million lawsuits against Ottawa but halted their legal proceedings to allow former Supreme Court justice Frank Iacobucci to conduct an internal inquiry. Mr. Iacobucci ruled in 2008 that Canadian officials were indirectly responsible for their torture.

With files from Steven Chase