Multiple witnesses to Wanaka helicopter crash that killed Nick Wallis, Paul Hondelink and Scott Theobold

Three Transport Accident Investigation Commission staff spent yesterday interviewing witnesses to Thursday's helicopter crash near Wanaka Airport, which killed three people.

Senior communications adviser Simon Pleasants told the Otago Daily Times there were "quite a lot of witnesses to the actual accident or just before or just after the accident" and witnesses were being spoken to while events were still fresh in their minds.

The bodies of the three victims — Nick Wallis, of Wanaka, and Paul Hondelink and Scott Theobold, of Twizel — have been taken to Christchurch for autopsiess.

Pleasants said the wreckage had been removed and was being taken by truck to Wellington for analysis.

"They try to put the pieces back together in a way that helps the investigation."In this case, there's quite a lot of complexity because of the heat of the accident.

"There was an intense fire."

He expected it would be 18 months to two years before the final report on "the likely cause and circumstances" of the crash was completed.

However, an interim report could be produced.

"Sometimes the commission turns up an aspect of an accident where there is a clear indication that something went wrong and they will issue an interim report."

In those cases that report can come out just in a few weeks.

"I'm not saying that that will happen in this one but that has happened."

He was not surprised there was speculation over the cause, Pleasants said.

"We can't comment on the circumstances of causes of accidents until the commission's final report is issued.

"That said, there were a lot of witnesses to this accident and it is not surprising people will talk about what they saw."