Jacques Shore, the lawyer, submitted before the commission that even after a Sikh extremist was arrested at Vancouver International Airport in March 1985 trying to board a flight with pieces of an Uzi submachine gun in his bag, security was not increased for flights connecting to Air India.

He said the bomb that brought down Air India was put aboard a CP Air flight in Vancouver that connected to Air India Flight 182. The passenger who checked the bag never boarded the connecting flight and was not even confirmed for the Air India flight.

The bombing of the AI flight 182 left 329 people dead on June 23, 1985.

"My question is whether CP was advised and alerted to the fact that there were threats to Air India flights, in fact, because of the connecting baggage and passengers," Shore opined.

He said the Royal Canadian Mounted Police had an obligation to make sure Vancouver's airport was secure given that police had already identified a group of Sikh extremists in British Columbia, including suspected bombing mastermind Talwinder Singh Parmar, as a threat.

"In the context of the security element, I think it is up to the RCMP to do what is necessary in the context of dealing with airports and the protection of persons," Shore said.

"If they would not be able to address these issues properly, then you get to a point where you say... we can't protect the public and there may have been a duty to warn them."

When the Vancouver suitcase arrived in Toronto, it was supposed to be X-rayed, but Air India's X-ray machine broke down earlier. The airline then brought in a handheld sniffer device to check for explosives.

But declassified documents released at the inquiry say the RCMP had warned Air India and Transport Canada six months earlier that the sniffer was "totally ineffective" for bombs.

Air India lawyer Soma Ray-Ellis said that despite the police warning about the device, Transport Canada had not prohibited its use. "It was the only available means of detecting handmade explosives at the time," she said.