The identity of the helicopter pilot who crashed into the roof of a luxury Cairns hotel remains a mystery, with shadowy CCTV footage of a pilot stealing the chopper from the airport among the only clues available so far.
Emergency services rushed to the scene after the twin-engine chopper hit the DoubleTree by Hilton hotel before 2am on Monday.
QueenslandPolice have confirmed the pilot - the helicopter's sole occupant - died at the scene.
Two hotel guests, an 83-year-old man and a 76-year-old woman, were taken to Cairns Hospital in a stable condition.
At a police briefing,Acting Queensland Police Assistant Commissioner Shane Holmes was asked: 'Does it look like a deliberate act or an accident?'.
He simply responded that was 'unknown at this stage', but believed to be an 'isolated incident'.
The helicopter slammed into the roof of the luxury Cairns hotel - with two of its propellers falling off on impact
All hell broke loose inside hotel rooms as the helicopter collided with the building
Nautilus Aviation, the company that owned the helicopter, confirmed that it had not authorised the helicopter's use, which was understood to have been taken from its hangar at Cairns Airport.
'Nautilus Aviation are working closely with Queensland Police, the Australian Transport Safety Bureau and other authorities as they investigate the unauthorised use of one of our helicopters in the early hours of this morning,' it said in a statement to Daily Mail Australia.
Nautilus Aviation chief executive Aaron Finn said none of the accredited pilots who work for Nautilus Aviation were flying the aircraft.
However he could not rule out if someone else in the company was responsible for the bizarre fatal flight.
'We have quite a lot of staff in the organisation. We can't identify (the person responsible) from CCTV footage, it's very dark,' he told The Australian.
Meanwhile, a witness described how the chopper flew around 'really fast' before hitting the hotel in a 'massive explosion'.
The aircraft slammed into a couple's hotel room window (above). The survivors were 'holiday makers' who had been asleep and were 'lucky not to be seriously injured'
'It was like a fuel tank exploding,' tourist Veronica Knight said.
Ms Knight said she saw the helicopter fly around for about 15 minutes, and described how she saw it going past her 'really fast' twice.
The Sydney tourist said she had never seen a helicopter travel so quickly.
'It came back real fast then went into the hotel. I was very scared,' she said.
'It was like an army helicopter but faster. Like a warplane, like it was going to come in and bomb you.'
Helicopter propellers fell to the ground in the crash, with one landing on the main street and the other in the hotel's pool.
'We saw the rotor on the ground. I wasn't far away. It could have got me,' Ms Knight said.
The crash sparked a fireball which prevented emergency crews entering the hotel immediately, Queensland Ambulance Service's Caitlin Denning said.
Acting Assistant Commissioner Shane Holmes would not confirm if police had positively identified the pilot and informed his next of kin
Tourist Veronica Knight shared shocking detail of how the crash unfolded - comparing the activities of the helicopter that passed over the city as like a warplane
'At the time, it was too unsafe for us to enter the hotel to view the (impact site),' she told reporters.
Queensland Police Service Acting Chief Superintendent Shane Holmes said police had launched an investigation to work out how the helicopter was taken.
'The aircraft was moved from a general aviation hangar early this morning, and it was an unauthorised flight.
'We are working with the local aviation operators to determine the circ*mstances leading up to before the aircraft went into the air.'
When asked about the identity of the pilot, Acting Supt Holmes said he was not sure.
'We have some preliminary information but we have no formal confirmation of identity.'
Police said the helicopter took off from Cairns Airport - where Nautilus Aviation has hangars (above) and was only in the air a short time before he crashed into the Double Tree Hilton 6km away
Stock image of a Nautilus helicopter from its Facebook page
Australian Transport Safety Bureau Commissioner Angus Mitchell dismissed speculation that an untrained pilot could have flown the helicopter.
'It's certainly very difficult to fly a helicopter if you do not have the experience,' he said.
Queensland Premier Steven Miles described it as a 'terrifying event'.
'I can't imagine how scary it would be to be asleep and to hear that bang and to have to be evacuated.'
DoubleTree by Hilton management said all guests and staff had been safely evacuated from the premises.
'We are actively arranging alternate accommodations for these guests for this evening,' a statement said.
