OTTAWA - Canada's spy watchdog says the Canadian Security Intelligence Service may need major changes after finding it ignored concerns about human rights and Omar Khadr's young age in deciding to interview the Toronto-born teen at a U.S. military prison.

The Security Intelligence Review Committee called Wednesday for "guidance and advice" from Public Safety Minister Peter Van Loan to help the spy service meet legal and public demands in the post-9-11 world.

"The time may have come for CSIS to undertake a fundamental reassessment of how it conducts business, and to undergo a cultural shift in order to keep pace with the political, judicial and legal developments of recent years," the committee said in a report on the Khadr case.

Khadr, 22, is being held by the Americans at Guantanamo Bay, Cuba, for allegedly throwing a grenade in Afghanistan when he was just 15, killing a U.S. soldier.

There was widespread media reporting on allegations of mistreatment and abuse of detainees in U.S. custody in Guantanamo and Afghanistan when the Canadian Security Intelligence Service put questions to Khadr in February 2003, the review committee report says.

"SIRC did not find any evidence that CSIS took this information into account in deciding to interview Khadr."

The committee also raised serious concerns about Khadr's age in the special report to Van Loan, responsible for CSIS.

"It is well recognized in Canadian and international law that youth are entitled to certain fundamental rights because of their status as a minor," the report says.

"SIRC found no evidence that CSIS took Khadr's age into consideration before deciding to interview him at Guantanamo Bay."

Documents have surfaced showing Khadr's American captors threatened him with rape, kept him isolated and would not let him sleep.

It has also long been known that CSIS officers questioned Khadr at Guantanamo in 2003 and that they shared the results of their interrogations with the Americans.

Public release of a video in which a teenaged Khadr cries for his mother sparked an international uproar last year.

At the same time, the Khadr family has gained notoriety for apparent long-standing ties to al-Qaida kingpin Osama bin Laden.

Omar's father, Ahmed Said Khadr, was a purported extremist and financier for the terror network. He was killed by Pakistani forces six years ago.

A brother, Abdul Karim, was left a paraplegic from wounds suffered in the shootout.

"I'm angry," the 20-year-old said from the Khadr home in Toronto after learning the review committee's findings about his brother.

"Everybody knows that he's underage, and the fact that they still interrogated him, that shows that they had no consideration for his age, or his mental status."

Overall, the review committee was "disconcerted" by the apparent lack of meaningful discussion of the issues within CSIS.

CSIS, which marks its 25th anniversary Thursday, rose from the ashes of the scandal-plagued RCMP Security Service.

The review committee said it hopes the changes CSIS has made in recent years on co-operation and information-sharing with foreign partners will help the spy service take human-rights issues into consideration in future probes.

It also recommends CSIS consider establishing a policy framework to guide its dealings with young people.

"As part of this, the service should ensure that such interactions are guided by the same principles that are entrenched in Canadian and international law."

In a broader vein, the review committee says it may be time for CSIS "to undertake a fundamental reassessment of how it conducts business" and urges it to introduce measures to keep pace with "growing and evolving expectations" of how an intelligence agency should operate in a democracy.

"To that end, it would be helpful if CSIS received guidance and advice from the minister on how to accomplish this task."

Review committee chairman Gary Filmon said in an interview "that these things are of such public sensitivity that the minister has to be involved in any significant changes of policy and process that they make."

There was silence from Van Loan on that point Wednesday.

But a spokesman for the minister said he was reviewing the report and noted the government had already issued new direction to CSIS on dealing with individuals under age 18.

CSIS said it welcomes a policy discussion about the role, mandate and expectations of an intelligence agency when operating abroad "as this function is vital to the security of Canadians."

However, the spy agency was quick to add that while it was aware of media allegations of mistreatment of Guantanamo detainees, it had no reliable proof that Khadr had been mistreated before interviewing him.

Khadr has spent more than six years at Guantanamo, the lone remaining westerner at the U.S. holding facility for prisoners in the war on terror.

A U.S. military commission is considering the charges against him.

Khadr's lawyers maintain the interrogation of Khadr made Canadian officials complicit in rights violations.

In May 2008, the Supreme Court of Canada ruled Canada had taken part in a foreign process that breached its international human rights obligations.

Successive governments, both Liberal and Conservative, have refrained from intervening in the case. The Tories have rejected a growing chorus of calls to repatriate Khadr and deal with him on Canadian soil.

The Liberals and NDP renewed those calls Wednesday on release of the review committee report.

"I think this is another indication of the Canadian government's failure to ensure that Mr. Khadr is treated in accordance with judicial principles that Canada upholds," said New Democrat MP Jack Harris.

Liberal MP Dan McTeague, who was the government point man on consular cases in 2003, said Khadr's "important fundamental rights" have been "ignored and sidelined."

The Federal Court of Canada ruled in April the government must ask the United States "as soon as practical" to return Khadr home. The government is appealing that decision.

The committee report warns that until CSIS receives clear federal direction on sharing countries with poor human rights records, "this very difficult issue will continue to plague CSIS decision-makers."

"More importantly, it will place the organization in an uncertain and vulnerable position when legal proceedings arise, as seen in the Khadr matter."

With files from Diana Mehta in Toronto.