A Qantas Airways flight from New Zealand landed at Sydney airport on Wednesday after the airline said it had issued a distress signal due to an issue with one of its engines.

The Boeing 737-800 jet from Auckland had issued a "mayday" call while flying over water an hour from its destination of Sydney, a Qantas spokesperson in a statement issued prior to landing.

The mayday signal, which indicates grave and imminent danger, was downgraded to “Possible Assistance Needed” before landing, the spokesperson added.

Emergency services met the plane when it landed in Sydney around 3.30pm local time (0430 GMT).

Qantas said it would share more information once the aircraft had been assessed by its engineers