By Kristy Sexton-McGrath, Christopher Testa and Sarah Richards for the ABC
The pilot who was killed when a helicopter crashed into a Cairns hotel roof in the early hours of Monday morning was a current ground crew employee, who had started working with the company four months ago.
Nautilus Aviation chief executive Aaron Finn confirmed late Tuesday afternoon that a member of their ground staff "gained unauthorised access to [the] helicopter hangar and misappropriated one of [the] helicopters".
He said the employee held a New Zealand pilot's licence but had never flown in Australia.
Finn said there was a gathering of company employees on Sunday night, including off-duty-pilots, celebrating a promotion of the man who flew the helicopter.
"This was a privately organised send-off for the individual involved in Monday morning's incident, who was recently promoted to a ground crew position at another one of our bases," Finn said.
"This was not a work event and had been coordinated by friends."
Finn said the company had undergone interviews with the Australian Transport Safety Bureau (ATSB) and Queensland Police Service.
Recording devices sent for analysis
Recording devices from the helicopter have been sent for analysis as the investigation shifts to the pilot.
ATSB chief Angus Mitchell confirmed earlier today, the helicopter's evidence, including technical instruments, had been sent to Canberra to be examined.
"We'll start analysing that to get a better idea of the flight plan, and indeed, once we get that confirmation of who was the occupant at the time and who was the pilot at the time," Mitchell said.
"Yesterday was very much focused on accessing the site itself."
Nearly 400 people were evacuated after the helicopter hit the hotel shortly before 2am on Monday.
Investigators believe the helicopter was taken from the Cairns Airport before flying into the no-fly zone over the CBD.
The probe will also involve the Department of Home Affairs, which oversees airport security.
"There are other aspects of this particular investigation that probably fall a little bit outside transport safety," Mitchell said.
"This is going to be an interesting one, a little bit different to what we would normally investigate."
Wreckage of helicopter removed from hotel roof
Witnesses reported seeing the helicopter flying at high speed and low to the ground along the foreshore before crashing into the building.
The wreckage of the helicopter was removed from the hotel roof last night.
Cairns Airport chief executive Richard Barker said airport security had not been compromised.
"Cairns Airport operates under an approved multi-layered transport security programme," Barker said.
"We have conducted a review this morning and initial findings show there has been no compromise of the airport security program or processes."
Doug Drury, head of aviation at CQUniversity, said aviation companies typically used keypads with codes for security.
"I've used them in airports all over the world but it's a common code and if you've ever worked at this location, then you would know where to go and how to get in," he said.
"They do change the codes and I imagine every facility at Cairns Airport now has a new code in their door and in their gate locks."
Professor Drury said Cairns Airport security was "right up there with everybody else's" but it was "a given that the security presence will increase".
"They'll go through footage from all the security cameras to see how this person got in and how they were able to start the aircraft," he said.
The Australian Federal Police said it was assisting the Queensland Police Service with inquiries related to the events at the airport and its surrounds.
It did not confirm whether an aviation security identification card (ASIC) was used to access the airside area.
This story was first published by the ABC.