AN AIRCRAFT passenger who allegedly tried to ignite explosives concealed in his shoes is British, Scotland Yard said last night.

The man, identified by French police as 28-year-old Tariq Raja, was being questioned by FBI agents in Boston.

American Airlines flight 63 from Paris to Miami was forced to make an emergency landing in Boston on Saturday after Raja allegedly tried to set off improvised explosives.

A Scotland Yard spokesman said last night: "It is believed he is a British citizen."

Earlier, French police claimed he was a Sri Lankan national travelling on a British passport. But in America, there were reports he was Syrian.

Terri Evans, press officer for the British consulate in Boston, said inquires were continuing into how the man acquired the passport.

She said: "We are still trying to confirm the details. We are trying to find out more about the circumstances of issuance of that passport."

Raja - 6ft 4in tall - was tackled by passengers and crew after a flight attendant smelt sulphur and believed he was attempting to start a fire. He was restrained and belted into his seat aboard the aircraft before two doctors sedated him with drugs from the plane's medical kit.

The jet, with 185 passengers and 12 crew, was escorted to Boston's Logan International Airport by two US F-15 fighter jets, landing at 4.50pm GMT.

Passengers described how they tackled the man. Thierry Dugeon, a 36-year-old television reporter from Paris, said the first he knew anything was wrong was when he heard a flight attendant ten rows in front of him shout for help.

He said: "I was there in five seconds, and there were already two or three guys on him.

"It was like everybody knew what they needed to do. It's pure instinct because it goes so fast. You're not going to think twice."

The Washington Post reported security sources were uncertain whether the shoe contained the powerful C-4 plastic explosive.

The American paper said sources had revealed that, although the explosive can be difficult to trace, security dogs had not detected it when they sniffed the suspect.

But Laura White, a spokeswoman for the Massachusetts Port Authority, which runs the airport, earlier claimed the shoes contained what looked like detonator wires.