Guilty? Airport believes a mallard duck is the prime suspect in Virgin emergency

Queenstown airport officials have revealed that their Airport Emergency Service (AES) team has the evidence that will help identify the cause of Monday's aircraft engine fire.

A Virgin Australia 737 had to divert to Invercargill airport on one engine after the other engine caught fire during the 6.00 pm take off from Queenstown.

The plane landed safely.

Airport staff say that their investigation should help discover the cause.

"Some bird remains were found at the far end of the runway and this information has been passed on to Virgin Australia to support with their investigation.

"The airline will carry out an investigation so we will refer to them for official confirmation of the cause of the incident."

Crux understands that the bird remains may be those of a mallard duck, but it will take more detailed work to confirm that information.

Video taken by a passenger on the Virgin aircraft clearly shows the engine catching fire after some type of incident or small collision just seconds after take off.