The plane turned back after a 'technical fault'

Flight VS45, with 181 passengers, had been two-and-a-half hours into the flight to John F Kennedy airport.

A Virgin spokeswoman said it was "purely a safety precaution" and the plane landed at Heathrow at 1345 GMT.

A BAA spokeswoman said: "The captain took the decision and if it had been more serious he would have landed at the nearest available airport."

The jet - an Airbus A340-300 - did not turn back because of any security problem, she added.

There was no danger to passengers and it was purely a safety precaution Virgin Atlantic spokeswoman

Emergency services were put on standby at Heathrow, but she said this was a routine measure in such cases.

"As one of the busiest airports in the world we have 1,250 flights in and out every day and we can have two or three such incidents daily."

Virgin Atlantic said the returning passengers would still be able to reach their intended destination.

"The captain decided to turn back just as a safety precaution because there was a smell of burning in the cabin. There was no danger to passengers and it was purely a safety precaution.