Because the first officer had not yet completed his pilot training, a passenger plane en route from London to New York via Ireland has turned around.

The airline Virgin Atlantic spoke on Thursday of a roster error.

The Airbus A330 had been in the air for 40 minutes on Monday when it was noticed in the cockpit that the first officer had not yet completed his last training flight and the captain is not qualified as an instructor.

They then flew back to London Heathrow Airport, where the plane landed a good 90 minutes after takeoff, the PA news agency reported on Thursday.

The first officer was replaced and the engine restarted.

The jet finally landed in New York two hours and 40 minutes late.

It was not initially known how many passengers were on board.

Virgin Atlantic said the first-placed first officer has been with the company since 2017 and is fully qualified under UK law to fly the aircraft.

However, he was still missing a final evaluation flight, which is part of the airline's internal requirements.

A UK Air Traffic Control spokesman said: "Both pilots were in possession of the appropriate license and qualified to conduct the flight."