The official spoke on condition of anonymity. Rolls-Royce has not commented on the engine replacement.
On Nov. 4, a Qantas A380 was forced into an emergency landing when one of its massive Trent 900 engines blew up over Indonesia. Leaking oil caught fire, heated metal parts and caused the explosion.
Qantas grounded all of its six A380s shortly after the incident and four days later, the company said checks had revealed suspicious oil leaks in three engines on three different grounded A380s.
Singapore Airlines and Lufthansa also use A380s with Trent 900 engines. They've conducted checks on their superjumbos and all but one have returned to service.
For Qantas, the removal and replacement of engines can cause delays and lead to potential revenue losses.
Monday, more trouble was reported for Qantas airlines, this time involving a 747.
The plane was heading to Buenos Aires, Argentina from Sydney when smoke started coming from an instrument panel in the cockpit about an hour into the flight.
The airline said the plane dumped its fuel, turned around and landed safely in Sydney.
This latest incident is not related to A380 problems.
The Associated Press contributed to this report.