06/11/2015 09:41 EDT | Updated 06/11/2016 05:59 EDT

Vancouver airport customs breach blamed on Air Canada employee

An Air Canada employee is at fault for Sunday's customs security breach at Vancouver International Airport, officials there say.

Three passengers bypassed customs and left the airport when passengers on a flight landing from Beijing were misdirected to the domestic terminal.

While the Canada Border Services Agency attempts to track down the three individuals who left without getting cleared by customs, the airport says it's implemented new measures that will prevent the lapse from happening again. 

"This is a very serious event," says Steve Hankinson, vice-president of operations and information technology at the airport. 

"We have worked closely with [Canada Border Services Agency], Air Canada and RCMP to ensure this type of thing never happens again."

Hankinson says the issue came down to a set of doors not being properly managed. 

"One set of doors leads to the aircraft. Another set of doors, if closed, direct the passengers to CBSA and if open, then lead you into the Domestic Terminal."

Air Canada won't say what kind of disciplinary action has been taken against the employee in question. The airline could potentially face a fine for misdirecting passengers.