Qantas will temporarily withdraw six aircraft from service after discovering an irregularity in paperwork during a routine check.
In a statement released on Tuesday night, the airline said it would withdraw the six B737-400s from service while it cross-checked maintenance records relating to work carried out at one of its Australian facilities.
Qantas has been under scrutiny recently over a spate of incidents, most notably an explosion that tore through part of the fuselage of a Boeing 747-400 en route from London to Melbourne.
Last week, a Qantas jet was grounded because of noise from an air-conditioning fault which was found on a plane that was returned from routine maintenance in Malaysia two months ago with 95 defects.
Qantas Engineering executive general manager David Cox stressed that the paperwork issue was related to procedure and did not have any safety implications.
"Qantas discovered an irregularity with paperwork for these aircraft during an internal integrity check of maintenance records," he said.
"In line with our prudent response to any maintenance issue, however minor, we have elected to suspend the operation of the six aircraft while we ensure all our records are 100% accurate and we have advised the Civil Aviation Safety Authority.
"We regularly check our records and detect a record-keeping anomaly on average once a year."
The sidelining of the aircraft resulted in the cancellation of three flights on Tuesday night.
Mr Cox said all passengers were put on to new flights within two hours of their original departure time.