OTTAWA - Lawyers for the families of the 1985 Air India bombing victims say they're dismayed by newly disclosed documents that indicate the Conservative government of Brian Mulroney refused to share a preliminary report on the tragedy with Indian authorities.

"We are pretty shocked by the stuff that we saw in there," Jacques Shore, one of the legal team representing the families, said Sunday.

"What is really clear is that they wanted to suppress this report at the time."

At issue is a study done by the Canadian Aviation Safety Board looking into the probable cause of the crash of Air India Flight 182 in June 1985 with the loss of 329 lives.

The safety board quickly concluded the plane was probably brought down by a bomb in a piece of checked baggage stowed in the forward luggage compartment -- an assessment that turned out to be correct.

But documents not publicly released until last Friday show that senior federal officials argued strenuously that the finding was "premature" at that time and was based on "inconclusive" evidence.

One memo, dated Jan. 23, 1986, refers to an inter-departmental meeting held seven days earlier that was chaired by Fred Doucet, then a senior aide to Mulroney in the Prime Minister's Office.

The memo notes there was "strong and sometimes heated discussion" at the meeting, with Justice Department lawyer Ivan Whitehall arguing "the report should not go forward" without further work.

The decision made at the meeting, said the memo, was to refrain from giving a copy of the report to a judicial inquiry set up by the Indian government under Justice Bhupinder Kirpal.

Instead, the author of the report was sent to India to give evidence that could be treated as "just another piece of testimony" rather than a conclusive finding.

Shore said he suspects the real reason Canadian officials wanted to withhold the report from public view was that it might have given legal ammunition to the victims' families in civil damage claim against the Canadian government.

That suspicion is buttressed, he said, by another document from Aug. 15, 1985, less than two months after Flight 182 was downed off the coast of Ireland.

This memo states that "if Justice Kirpal determines that Canada is blameworthy by virtue of its inadequate security measures, and even if the courts in Canada do not subsequently find liability, the political and financial costs may be unavoidable."

The bottom line, said Shore, is that Canadian officials wanted to pretend they knew less than the did.

"It would be too much heartburn from having to accept the truth . . . People weren't willing to accept the bad news that clearly was out there."

Shore and co-counsel Norn Boxall made the same point in a written submission to Canada's own belated public inquiry, headed by former Supreme Court judge John Major.

"The government of Canada intended to suppress the CASB report, believing that its conclusions could be damaging to the case the government was trying to build," they wrote.

The Major inquiry wrapped up its public hearings in February 2008 but has continued to work behind closed doors since then. The memos released last Friday were the latest in a series of documents to be made public in recent months.

Major had hoped to have a final report by June, but insiders say it now appears likely it will be pushed back until the fall.

The Air India bombing was blamed on Sikh terrorists operating from a base in British Columbia, but only one man has ever been convicted, on a reduced charge of manslaughter.

Another was shot dead by police in India and two more were acquitted at trial in Vancouver -- a verdict that sparked outrage among the victims' families and led to creation of the Major inquiry.