Air Canada [Images] is worried about its front-line staff who would cross-check passengers with names of suspected terrorists or their supporters on the controversial new no-fly list and handle the situation, the Air India inquiry was told.

Yves Duguay, Air Canada's head of security, said while the airline supports the concept of the list that aims to identify people deemed to be threat to aviation security, there is some concern about how to deal with someone at airport who learns they are on the list.

The Canadian version of the list will be in place starting next Monday and it will be airline staff who have the task of cross-checking passengers with names of suspected terrorists or their supporters on the list.

If a hit is found, they are supposed to notify police, but also explain to the passenger why they cannot board the flight.

Duguay said that could lead to tension.

"It could turn to an unruly situation very quickly when the person finds out that they cannot fly," Duguay, a former Royal Canadian Mounted Police officer, told inquiry head John Major.

"There is the possibility that the situation could be very tense and we have to have an authority figure in place to diffuse that situation. So we want to make sure we have a police presence, not only in Canada but that this is something that should also be addressed abroad because of the type of situation we have," he said.

Till date, Air Canada was supposed to identify people flying to and from the US-based on that government's list. But in some cases, the same people were booked on Air Canada flights in other parts of the world, making it a continuing concern for airline security, he said.

Canada's privacy commissioner Jennifer Stoddart has said the list could become 'quite a nightmare' for ordinary Canadians.

"Every time we go to the airport, do we expect to be challenged? That may be the new world," she said. But Duguay said the list is based on intelligence gathered, so is likely to be very short and the incidents of its use by airlines rare.

Raj Anand, a lawyer for victims' families, asked if Air Canada is supposed to share the list with representatives of foreign governments.

Last week, a Transport Canada official testified at the inquiry that it was possible the information could end up in another government's hands.

Duguay said that obviously Air Canada would be very careful with the information, but would need to share some of it with police at foreign airports if they need help at an airline counter with a passenger.            

Duguay, who also chairs a security committee at the International Air Transport Association, said Air Canada continues to work with Transport Canada on its concerns over the application of the list.

"As the deadline looms, at Air Canada we will undertake to contact local police forces when we have identified an exact match to our system," he said.