A Pakistan International Airlines jet is shown here taxiing. (CBC)

A CBC News investigation has revealed that on Aug. 7, 2009, Transport Minister John Baird issued a secret ministerial security order involving Pakistan International Airlines, which operates at Toronto's Pearson International Airport.

Section 4.72 of the Aeronautics Act was created post-9/11 but appears to have never been used until the summer of 2009.

The section allows the minister to create and impose security measures when a situation demands immediacy and secrecy. He can institute measures without consulting anyone, " … if, in the opinion of the minister, the security measure is immediately required for aviation security …." The legislation also prevents CBC News from reporting the substance of the measure ordered last August.

A security official at the airport, who asked not to be named for fear of losing his job, however, said that the measure wasn't handled in accordance with Greater Toronto Airport Authority security protocols and lives were potentially in danger.

"Lives are at stake," he said. "You do what you can and this wasn't done here." It is unclear whether the measure was taken in response to an imminent bomb threat. When CBC News contacted Baird's office asking what the nature of the threat was, the reply did not answer the question, but said, "Transport Canada continuously monitors information from many available sources to assess current and evolving threats."

Even though neither Transport Canada nor any other security agency will confirm the source's information, he says a story about an international bomb plot emerged a few weeks after the measure was put in place. He said the story originated with Transport Canada.

The source said bomb-making materials were going to be smuggled on a Pakistan International Airlines (PIA) flight headed for Pearson. Once in Canada, the materials would be made into a bomb and put back on a PIA aircraft.

"And it would explode somewhere on its return back to its origin," said the source.

The source went on to say the purpose of putting explosives on the flight departing Canada would be to place suspicion on individuals in this country, rather than in Pakistan.

The source said that the manner in which Baird's order was carried out could have resulted in additional lives being lost in the case of an explosion.

Sources at the airport told CBC News that Pakistan International Airlines planes were never moved away from the gate while they were searched for explosives. Pearson airport has places for aircraft isolation, so that if there were an explosion, at least it would be far from the terminal.

The bomb threat protocols of the Greater Toronto Airport Authority (GTAA) state: "If for any reason the affected aircraft cannot be taken to a designated holding area, it will be isolated in its existing position at least 150 metres from any other aircraft, structure or active operational surface."

Baird is not bound by GTAA protocols, but the source said it just makes sense to move a plane suspected to be carrying explosives away from buildings.

"The public is right there. It's like having an explosive vehicle in downtown Toronto. You can think of the numbers of people who are at a major airport in this country at any given time or on any aircraft at Pearson International, tens of thousands. Let alone people who have to work around it. There's a lot of fuel on those aircrafts. There's fuel on other aircrafts that surround it. It would [have been] catastrophic if something had happened."

Under the Security Offences Act, when a crime is intended to cause serious violence, the RCMP will investigate. The GTAA protocols state: "Where the incident is an offence under the Security Offences Act, i.e. has national security implications or is politically motivated, the RCMP will be notified and may respond as federal police. Senior police officials will determine which agency assumes command of the response and investigation."

It is unclear whether the measure was ordered in reference to a threat to national security, but a spokesman for the RCMP told CBC News that the Federal Enforcement Division at Pearson was never briefed on Transport Canada's August security concerns and that the agency took no action in relation to it. He added an RCMP Integrated National Security Enforcement Team may have been involved, but the team did not respond to a query from CBC News.

Unofficially, a source with RCMP national security said the Mounties didn't believe the threat constituted a national security threat, and that they took no further action on it. Why Transport Canada would undertake an immediate, top-secret ministerial order, while the national police force appeared to be unfazed, is unclear.

The police department with jurisdiction at Pearson, the Peel Regional Police Force, usually deals with non-federal Criminal Code matters at the airport. They are called on by GTAA bomb threat protocols to: "…investigate all bomb threats regardless of threat assessment."

Sources at Pearson told CBC News that there were no police in sight while the minister's order was being carried out.

Peel police Supt. Mike MacMullen would neither confirm nor deny the force's involvement saying, "I am confident in light of the partnerships that exist out here at the airport that if there was a serious threat to aviation that we as the police service of jurisdiction would be informed, and the actions that we take would be driven by the circumstances of that incident … They could fit into a range of very little involvement to actually taking it over."

Transport Canada is not obligated to share intelligence with an airline, but the government's own protocols, the Canadian Aviation Security Regulations, say under section 56(1), "An air carrier that determines that there is a specific threat that jeopardizes the security of an aircraft or flight must immediately take all of the measures necessary to ensure the safety of the aircraft and the passengers and crew on board the aircraft …", But according to a representative with PIA, they did not get the chance.

According to the representative, Transport Canada officials said they would be undertaking the security measure because they had some security concerns and did not give any information on what the concerns were. When asked if the airline was told the measure concerned the possible transportation of explosives on the carrier's aircraft, he said he could not remember. According to the representative, the airline didn't know there was a special ministerial order concerning its aircraft.

When the Canada Border Services Agency, the agency responsible for screening international arrivals, was asked if it was aware of the measure and whether it had any involvement, a spokesperson was unable to find any information relating to special Transport Canada security measures issued in August. Adding in a further statement, "The CBSA works closely with other government departments in ensuring the safety and security of Canadians. This is a Transport Canada initiative, please direct your questions to Transport Canada and/or the Greater Toronto Airport Authority."

Two sources at the airport said the GTAA had a direct role in carrying out the security measure. But in a statement to CBC News, the GTAA also redirected queries, saying, "Questions about the security directive(s) should be addressed by Transport Canada."

When Baird was told CBC News was looking for a response to specific security concerns that have been raised in relation to how the measure was executed, the minister's office replied in an email, " … As [a] matter of routine, these measures are monitored and where adjustments are required, they are made."

Baird refused an interview with CBC News when asked in late 2009. His office has said he will be available for an interview with CBC Thursday.

The Canadian Air Transport Security Authority has not responded to questions from CBC News.

Sources at Pearson said Baird's order is no longer being followed. The measure was undertaken consistently at first, but after a few weeks in, following a disagreement over who would cover the costs, sources say it was performed less frequently, and eventually, not at all.

Whether or not the threat has passed is not clear. A CBC News source close to the investigation said, "I have no knowledge the threat was reduced and nobody ever said that it had been. It still remained the same, the same information."

The fact that the measure is no longer being undertaken suggests the threat is gone, but it seems Baird still has some concerns. The Aeronautics Act says that if the minister is of the opinion the security of the public, aircraft or airport would no longer be in danger if the particular matter in the measure was made public, that he must, "within 23 days after forming the opinion, publish in the Canada Gazette a notice that sets out the substance of the security measure …"

To date, the substance of the measure has not been published in the Gazette.

Investigations@cbc.ca