The Canadian government has rejected demands for a probe into what the country's intelligence agency, whose agent had infiltrated a Sikh militant group prior to the Air India bombing in 1985, knew about the tragedy.

Solicitor General Wayne Easter on Monday said he wouldn't comment on allegations that the Canadian Security Intelligence Service knew about the Air India bombs ahead of time except to reject them.

"Protecting Canada and Canadians from acts of terrorism has been a primary mandate of CSIS since its inception in 1984."

"To suggest that the CSIS, for any reason, would pull back from an ongoing counter-terrorism investigation and jeopardise the lives of Canadians and others is absolutely absurd," Easter said.

"This has been the longest, most costly investigation in Canadian history and my interest and Canadians' interest is to see it carried out through to its conclusion in court," Easter said adding, "I won't jeopardise the case by making comments that would be misconstrued."

Canadian opposition parties had called for a probe into accusations that the intelligence agency blocked a police investigation into the Kanishka bombing case.

In the House of Commons, Canadian Alliance MP Kevin Sorenson pressed the government to hold an inquiry into the allegations.

Documents released late last week indicated that the spy agency had a mole inside the Sikh separatist movement allegedly behind the June 1985 bombing that killed all

329 people on board Kanishka off the coast of Ireland.

Hours earlier, two baggage handlers died in an explosion at Tokyo's Narita Airport.

Around June one, allegations emerged that a CSIS informant, identified as Surjan Singh Gill, was apparently aware that something untoward was about to happen. He was ordered to pull out three days before the attack.

The spy agency is accused of failing to warn police of the impending attack. It also ordered the destruction of hundreds of wire tapes to cover up any evidence that it knew about the planned bombing.

The MPs want a probe into CSIS' link to the Air India plot.  They have demanded an inquiry into how much CSIS knew about the impending tragedy, and why the agency did not warn the police.

"Obviously, they were well aware that the bombing was going to happen," says Canadian Alliance MP Randy White. "The question then is: Why wouldn't they have passed that information over to the Royal Canadian Mounted Police, possibly preventing this whole bombing disaster in the first place?"

By erasing wiretaps, it appears that CSIS was 'prepared to effectively jeopardise a successful prosecution' just so that its informant was not implicated, Robinson said.

Two men, Ripudaman Singh Malik and Ajaib Singh Bagri, are currently on trial for the bombings, facing charges of murder and conspiracy. Another, Inderjit Singh Reyat, is serving a five-year sentence after pleading guilty to manslaughter.

Complete Coverage: The Kanishka Bombing