Montreal authorities questioned a man pulled from a WestJet flight bound for Toronto after he started behaving suspiciously moments before takeoff.

The 10:15 a.m. flight was grounded and the man was escorted off the plane by RCMP officers.

Passenger Boris Brott said the plane appeared secure for departure when police boarded the aircraft.

They "removed a gentleman who was seated behind me, and his luggage, and then the captain came on the communication system to explain that there had been a security breach, and that it would take some time," he told CBC News in a telephone interview from the airport gate.

Brott, an internationally renowned orchestra conductor, said all remaining passengers were asked to get off the plane and were placed in a closed room to undergo security screening. Montreal police then boarded the plane with dogs, he said.

Several other flights were delayed around the time of the incident, but no other departures or arrivals were affected, authorities at the Montreal Trudeau airport said.

The WestJet flight eventually took off at 2:42 p.m.

The suspicious passenger was transferred to a station in Montreal's west-end for questioning and was released afterwards with no charges.

WestJet spokesman Robert Palmer said the plane is a 136-seat 737-700 series aircraft with 90 passengers on board.

The airline will not comment any further, Palmer said.