OTTAWA - Pressure is mounting on the federal government to scrap a policy that sanctions the use of torture-tainted information in exceptional cases.

Amnesty International Canada and the official Opposition urged the Conservatives to impose a total ban on material gleaned from abuse and mistreatment, saying Thursday there can be no exceptions when it comes to torture.

Controversy has raged this week over revelations the government directed Canada's spy agency to use information that may have been extracted through torture in cases where public safety is at risk.

The government once insisted the Canadian Security Intelligence Service would toss out such information, but is now telling the spy service to act on it to protect lives or property.

A copy of the two-page directive, issued in December 2010 by Public Safety Minister Vic Toews, was obtained by The Canadian Press under the Access to Information Act.

It says that in "exceptional circumstances" where there is a threat to human life or public safety, urgency may require CSIS to "share the most complete information available at the time with relevant authorities, including information based on intelligence provided by foreign agencies that may have been derived from the use of torture or mistreatment."

In such rare cases, it may not always be possible to determine how a foreign agency obtained the information, and that ignoring such information solely because of its source would represent "an unacceptable risk to public safety," Toews adds.

In a letter to Toews and CSIS director Dick Fadden, Amnesty International Canada called on the government to broadly interpret article 15 of the United Nations Convention against Torture, which prohibits the use of information derived through mistreatment as evidence in any proceedings.

That prohibition should extend well beyond official legal proceedings, Amnesty argues.

"The spirit of the ban in article 15 is clearly an attempt to dry up the market for torture," says the letter. "If governments are prohibited from making use of information gleaned through torture carried out or condoned by other governments, there is one less incentive for those governments to carry out torture in the first place."

In the House of Commons, New Democrat MP Joe Comartin chided federal ministers for saying it would be irresponsible to ignore information -- even a possibly tainted tip -- about a bomb threat at the Air Canada Centre in Toronto or against a plane load of Canadians.

"All of this is to back up their irresponsible message to other countries that Canada is in the market for information based on torture. The government should oppose torture, no question about it," said Comartin.

"When will it rescind the directive?"

Defence Minister Peter MacKay stressed the federal position that "Canada does not condone torture and does not use torture. However, Canada will use information to save lives."

Ottawa lawyer Paul Champ, who has fought many human rights cases involving security issues, scoffed at the "ticking time bomb" scenario, calling the made-up notion of an eleventh-hour rescue a convenient means to justify the use of dubious information.

"They can't point to one example of that ever happening before."

He points to the case of Ahmad El Maati, a dual Canadian-Egyptian citizen who was arrested in November 2001 upon arriving in Syria, where family and friends planned to celebrate his marriage.

False confessions El Maati made under torture -- including a fictitious plan to attack the Parliament Buildings -- were used to obtain search warrants in Canada.

In turn that led to increased surveillance of other Arab-Canadians including Maher Arar, who would also be tortured in a grim Syrian prison. The federal government later apologized to Arar and gave him $10.5 million in compensation.

In a blog posting this week, Arar said that instead of clarifying Canada's position on the use of information obtained under torture, the federal directive "adds confusion to an already ambiguous and polarized debate."

"One thing is also sure: this directive is sending the wrong message to dictatorial regimes; you torture and we will return the favour by accepting and using your information."

A total ban on the use of information that may have been elicited from torture is too far-reaching, said Craig Forcese, a law professor at the University of Ottawa.

Such information should not be used in court or to arrest others, Forcese said, but could legitimately be used, for instance, to bolster security on a subway platform to guard against a possible terrorist bombing.

"Imagine if the bomb did go off and CSIS hadn't passed on that tip."