The Mounties are investigating a possible terrorism hoax after receiving a tip that a male passenger had a bomb on a flight from Toronto to Pakistan. The plane had to be diverted to Sweden, but no explosives were found.

The passenger, whose name has not been released, was detained and then released.

RCMP spokesperson Sgt. Marc LaPorte said an anonymous female caller phoned police twice on Friday saying a man aboard the Pakistan International Airlines flight had explosives.

"The first call provided vague information. It did lay out that there was an individual on that specific flight in possession of explosives and then the second call provided more details with regards to the identity of the person," LaPorte said.

LaPorte said it appears the caller may have had a grudge against the man.

"If the Swedish authorities are saying that they released him and there is no investigation on their end, we will obviously pursue this as a hoax," LaPorte said, adding charges could include public mischief.

Erik Widstrand, a spokesperson for Stockholm police, said the local prosecutor decided to release the man after he was questioned by investigators. "He was calm but irritated," Widstrand said, adding police will help him get on another flight to Karachi either late Saturday or early Sunday.

Flight PK782 from Toronto to Karachi was diverted to Stockholm after Canadian officials received the telephone tips.

The pilot requested permission to land at Stockholm's Arlanda International Airport after he received word of the potential threat.

The man was detained as a SWAT team evacuated the plane and searched for explosives, said police operation leader Stefan Radman. No explosives were found on the man, the Boeing 777 or the passengers' luggage.

The passengers were allowed back on the plane after nine hours in the airport terminal, said Jan Lindqvist, a spokesperson for airport operator Swedavia. The plane took off for Manchester, England, and from there will continue on to Karachi.

Little information has been released about the man who was detained. Airline spokesperson Sultan Hasan described him as a 25-year-old Pakistani national, while Swedish police said he is a Canadian citizen born in 1982. Police also said the man cleared security checks before the flight took off from Toronto, and was not on any international no-fly lists.

A spokesperson for the Department of Foreign Affairs in Ottawa had said Canadian officials were monitoring the situation.

"The Canadian Embassy in Stockholm is in contact with local authorities to gather additional information and stands ready to offer consular assistance as required," Alain Cacchione told The Canadian Press in an email before the man was released.

The other 254 passengers and 18 crew members that were on board the aircraft were taken to a lounge inside the airport, where they were given food and drinks, airport spokesperson Anders Bredfell said. Crisis counsellors were also on hand, he said.

The airline said there were 102 Canadian nationals on the flight, 139 Pakistanis, eight U.S. citizens, three people from India and one person each from Japan, Malaysia and Bangladesh.

With files from The Associated Press