Jetstar spokesman Simon Westaway said the aircraft travelling from Brisbane had landed and was stationary at the Newcastle airport terminal, when a ground crew member noticed a fire in one engine.

"The number one engine on the left side of the Airbus 320 caught fire briefly about 6.30pm (daylight savings time) while the pilot was shutting down the engines," Mr Westaway said.

"We believe that there was some residual fuel in the vicinity of the where the fire occurred. It is unusual...obviously that shouldn't occur."

Mr Westaway said the engine would be replaced today.

"We undertook an internal investigation last evening and decided that we will undertake an engine change."

Mr Westaway said the airline would examine to engine today to determine if a mechanical fault was responsible for the brief fire.

"That's what we're going to try and get to the bottom of today," he said.

Passengers booked on the return flight to Brisbane were given overnight accommodation while the the aircraft was inspected.

"Those customers going back to Brisbane were on our first flight this morning, which left a 6.30am," Mr Westaway said.

- with AAP