Thousands of air travelers had to face delays and cancellations due to widespread computer meltdown that was noticed at 9am on Sunday.

Air New Zealand's passenger check-in cabins, online bookings as well as call centre systems suffered failure of computer system.   

Air New Zealand staff had to book flights manually during the glitch.

Though the system returned to operation at about 3.30pm, yet the glitch caused multiple backlogs.

At around 5pm, Bruce Parton, spokesman for Air New Zealand, said that the schedule was returning to normal as the glitch was cleared.