Malaysia Airlines has admitted Auckland air traffic controllers were given the wrong flight plan for a flight taking off for Kuala Lumpur early on Christmas Day.
The airline is investigating the mix-up which happened when the Airbus A330, Flight MH132, left Auckland International Airport and the pilot quickly queried why air traffic controllers were giving him different directions to his own flight plan.
He had been expecting to take a more direct route to the Malaysian capital but was being told to fly in the direction of Melbourne before turning northwest, which he did.
In a statement, the airline says the flight crew were given a flight plan on Christmas Eve but "Auckland's Air Traffic Control was inadvertently given an earlier flight plan".
Both routes were an approved flight path and the aircraft had enough fuel for both routes, it said.
"The safety of both passengers and crew were never compromised at any time."
It is not known how many were aboard the A330, which can carry 283 passengers.
Malaysia Airways was last year hit by the loss of two of its aircraft, with Flight MH370 disappearing between Kuala Lumpur and Beijing and Flight MH17 shot down over the Ukraine.
Airways Corporation, New Zealand's air navigation service provider, says it is also investigating the flight plan incident.
Depending on the outcome of the Airways Corp investigation, the Civil Aviation Authority may investigate.