Malaysia Airlines has admitted a botch-up and launched an investigation, after a pilot who took off from Auckland Airport found his plane headed in the wrong direction.

Eight minutes after taking off last Friday morning, the pilot of the direct flight to Kuala Lumpur noticed the plane was travelling further south than he had planned.

He contacted air traffic controllers at the Auckland Oceanic Control Centre, and was told the airline had decided on the slightly different route.

Malaysia Airlines says it has launched an investigation, but passengers were not at risk from the error.

On Monday, Malaysia Airlines confirmed it had "inadvertently" given different flight plans to the air crew and Auckland's Air Traffic Control Centre.

"Our flight MH132 from Auckland to Kuala Lumpur was given the latest flight plan by the airline's Operations Dispatch Centre (ODC), while Auckland's Air Traffic Control (ATC) was inadvertently given an earlier flight plan," Malaysia Airlines said in a statement.

"Both routes were following an approved flight path and the aircraft had enough fuel for both routes. The safety of both passengers and crew was never compromised at any time.

"Malaysia Airlines is currently conducting its investigation in the flight plan submission. Safety is of the utmost priority for Malaysia Airlines and it adheres very strictly to all safety procedures and processes."

The airline did not explain why the two flight plans differed, or how the error occurred, but said flight plans were generated based on conditions at the time, including weather, efficiency, and air traffic notices.

That was in line with an earlier explanation from Airways, which said the glitch could be explained by a miscommunication of plans.

Airlines communicate their planned route to Airways, and that is passed on to air traffic controllers. Air traffic would then direct the flight's take off and landing, and a route would be programmed into the plane to provide turning points and direction for the pilot.

"The flight path the airline filed us was going to Kuala Lumpur, but following a slightly different flight plan that the pilot had on board," a spokesperson said.

"Quite quickly after taking off, the pilot realised that the direction that we were sending him in was different."

The plane was headed towards Melbourne, rather than taking a more direct route to the Malaysian capital.

No danger at any point

After talking to the bemused pilot, Airways uploaded their flight route to the airborne plane.

The pilot adjusted to the surprise, continuing across the Tasman Sea before heading north-west to the destination.

The spokesperson said the new route was in fact an established flight plan to Kuala Lumpur - but not the one the pilot had planned to follow.

Airways is also looking into the incident.

The spokesperson said passengers on board the flight were at no point in any danger, as the flight was still under radar control.

The glitch comes after a precarious couple of years for Malaysia Airlines.

Flight MH370 disappeared between Kuala Lumpur and Beijing in March 2014 with 227 passengers and 12 air cabin crew.

Then flight MH17 was shot down by a Russian-made missile over Ukraine in July 2014.

Airways said it didn't think passengers on board the flight were made aware of the glitch, and no time was lost due to the mistake.

- Stuff