SYDNEY - QANTAS said on Friday a mid-air drama involving a flagship A380 superjumbo may have been caused by a design fault in its Rolls-Royce engines, raising questions over the giant long-haul craft.

Chief executive Alan Joyce said early investigations pointed to a 'material failure or a design issue' in the Airbus plane's engines after one exploded minutes after take-off from Singapore, prompting an emergency landing.

'This is an engine issue and the engines were maintained by Rolls-Royce since being installed on the aircraft,' Mr Joyce told reporters at the Australian flag-carrier's Sydney headquarters.

'We believe that this is most likely some kind of material failure or a design issue... we dont't believe this is related to maintenance in any way.' The comments are the first to shed light on Thursday's events, when engine casing rained down on an Indonesian town and the superjumbo with 466 people on board dumped fuel before returning to Singapore.

The drama has thrown the A380 - the double-decker giant touted as the future of long-haul travel - into the safety spotlight three years after it took to the skies.

Rolls-Royce urged airlines to carry out 'basic precautionary checks' on its Trent 900 engines after the incident. Some 37 of the giant planes are currently in use around the world.

Qantas fears 'design issue'