Former justice of the Canadian Supreme Court John Major, who is currently heading the inquiry into the 1985 bombing of Air India Flight 182, has accused the federal government of attempting to cast doubt on the testimony of a key witness.

The controversy stems from the testimony of Ontario Lieutnant-Governor James Bartleman, who at the time of the bombing was employed in the Canadian foreign affairs department, that he had seen an electronic intercept, days before the June 23, 1985, bombing of the Air India Kanishka, which warned that Air India would be targeted by terrorists.

The intercept, Bartleman said, had warned that an Air India flight would be hit 'the coming weekend'. The Kanishka exploded in mid-air June 23 -- a Sunday.

Bartleman's testimony goes against the official position of the Canadian government, which in the over two decades since the tragedy has rigorously maintained that it had no advance intimation of any specific terrorist activity.

The Canadian government has repeatedly said that while there were generalised warnings of possible terrorist acts, there was never any specific intelligence indicating that a particular Air India flight would be in jeopardy.

Bartleman's testimony indicates the exact opposite -- that not only was there specific intelligence about the carrier, but also about the possible date, or time-period, in which the attack would take place.

Major, presiding over the ongoing inquiry into the clash, was moved to intervene during the testimony of Gordon Smith, Bartleman's former boss at the foreign affairs department.

Reporting on the incident, the Globe and Mail quotes Major as saying there appeared to be an 'effort by government to discredit Mr Bartleman', and that it appeared Smith was part of that effort.

'I'm not questioning your sincerity, but it's obvious that they don't like that testimony (by Mr Bartleman),' the Globe and Mail quotes Major as saying. 'You are one of several who seem upset by that evidence.'

Smith denied Major's accusation, and said he was not part of any 'campaign' to undermine Bartleman's credibility. The Globe and Mail however reports that Smith questioned whether his erstwhile colleague's memory of the incident was accurate, and asked why, if he was sure of his facts, he did not immediately alert his superiors, instead of waiting for 22 years before going public.

'I am upset by his evidence because if there was a senior officer reporting to me who had information that, if correctly used might have stopped this disaster, I have a feeling of responsibility,' the Globe quotes Smith as saying.