The Australian Transport Safety Bureau is investigating a Jetstar Airbus which flew below the safe level while descending into Queenstown.
The incident occurred on 16 July this year during a flight from Auckland to the South Island resort town.
The bureau says the crew had an incorrect descent profile selected and subsequently flew below the minimum safe altitude.
In a statement on Friday, Jetstar says the flight landed safely in clear conditions, however the pilots reported that on approach an incorrect autopilot setting resulted in the plane going off its pre-determined track.
Jetstar says this never put the aircraft in danger and the incident did not trigger any alerts in the cockpit.
The airline says the pilots realised the error and corrected it promptly.
