A helicopter crash off Queensland's Whitsunday Islands has left two people dead, with authorities set to launch an investigation.
The Civil Aviation Safety Authority says five people were aboard the Eurocopter 120 which went down near Hardy Reef Pontoon at about 4.30pm on Wednesday.
As well as the fatalities it's understood one person was seriously injured while the two others escaped with minor injuries.
It's also understood the helicopter crashed into water 250 metres from the pontoon.
The Australian Transport Safety Bureau (ATSB) issued a release on Wednesday evening confirming a crash investigation was being launched.
"A team of Transport Safety Investigators will soon travel to the accident location to commence the evidence collection phase of the investigation," an ATSB statement said.
"There, investigators will interview witnesses, examine any available recorded data, review operational records and technical documentation amongst other activities."
An expected timeframe on the investigation won't be known until the evidence collection phase is completed.
It's unclear at this stage if the flight was a private charter to the popular tourist destination but at least one helicopter tour operator in the region operates the type of aircraft involved in the accident.
Police and other emergency services were still attempting to reach the crash site by boat, which is 65km northeast of the Whitsundays.
The pontoon allows underwater viewing chambers with tourist operators in the area saying Hardy Reef offers an excellent combination of reef, coral and fish life for tourists.
The well-known Heart Reef is also nearby.
