All six people onboard a seaplane that crashed into the Hawkesbury River near Sydney have died, NSW police say.
Oil and debris were earlier seen at the scene of the crash, in Cowan Creek.
The seaplane crashed in Sydney's north at 3.15pm today.
No information is available on the identity of the occupants at this stage.
The crash site is about two kilometres north of Cottage Point.
A Sydney Seaplane spokesperson confirmed that it was one of their aircraft that had crashed but couldn't provide any further information.
"Obviously we are very concerned and trying to determine the details at this point. We are working with police at this time," he said.
Dozens of A-list celebrities have taken to the skies on-board Sydney Seaplanes to take in the breathtaking sights of the city and dine in the picturesque waterside restaurants on the Hawkesbury River and Palm Beach.
From royal sister-in-law, Pippa Middleton to TV host Jeremy Clarkson, an A-lister's favourite thing to do in Sydney is lunch at top peninsula restaurants Jonah's at Whale Beach, or the Cottage Point Inn, via Sydney Seaplanes.
Pop stars Sam Smith, Ed Sheeran, Ronan Keating and his wife Storm are also among celebs who have flown out on the trip.
Jerry Seinfeld, Ed Sheeran, Bill Gates and Sam Smith have also had a taste of the premier "fly and dine" experience.
Oscar-winning actor Cuba Gooding Jr, 49, chose the seaplanes as his favourite mode of transport while in Sydney early this month to film commercials for Optus.
The Australian Transport Safety Bureau said it will be "investigating the ditching of a single-engine seaplane which crashed at Cowan Creek, Hawkesbury River, NSW this afternoon."
"Three Transport Safety Investigators from Canberra will travel to the site shortly to begin their investigation.
The ATSB encourages anyone who witnessed the accident to call 1800 020 616 and register their details."
"It was pretty bumpy coming into the river valley before we landed for lunch," the ihug co-founder Mexicali shareholder said.
He said Australian music producer Alison Wonderland had also taken the same flight the following day.