The safety warning was issued before the arrival of Australia's Transport Safety Bureau's preliminary report which is looking into the engine failure of Qantas flight QF32 last month.
The defect is said to be related to an oil tube connection in the Rolls-Royce Trent 900 engine and is believed to be the cause of the engine failure of flight QF32, according to media report.
The ATSB said that the problem was caused by the 'off-axis' boring of the oil tube that supplies the engine bearing with oil, resulting in a thinning of the material on one side that 'could lead
to fatigue cracking, oil leakage and potential engine failure from an oil fire'.
Qantas is also probing into series engines 'B' and 'C' to check for evidence of the flaw using 3D-imaging equipment.
Qantas said the discovery of the defect 'appears to provide a more definitive explanation for the engine failure that occurred on QF32'.
Qantas said it did not anticipate at this stage that the inspections will have an impact on international services, but that contingency arrangements will be in place, if needed.