Six people are dead with three bodies still to be retrieved after a seaplane crashed into the Hawkesbury River in the Australian state of New South Wales.
The Sydney Seaplanes aircraft was carrying a pilot and five passengers when it crashed at Cowan Creek, Jerusalem Bay, on the Hawkesbury River east of Cowan about 3pm today.
Emergency services including the Westpac Life Saver Rescue Helicopter were called to the scene with police commencing a search and rescue operation to locate the plane, which is submerged.
Three bodies have so far been recovered as police divers attempt to recover the other three bodies, NSW Police say.
"We are in the process of recovering the bodies of three other people ... (we will) see if we can recover the plane tonight or whether it will stay in situ tonight until tomorrow morning," acting Superintendent Michael Gorman told reporters on the scene on Sunday.
"We don't know why the plane crashed."
The plane was believed to have been travelling from the picturesque Cottage Point Inn to Rose Bay, Supt Gorman said.
Police said they did not know the cause of the crash, nor the identities of the five passengers, but were speaking with several witnesses who were in boats on one of the waterways' busiest days of the year.The pilot was the sixth victim.
Several Australian media reported that four of the victims were British nationals, although that was not immediately confirmed by police.
In London, the Foreign Office said its officials were in contact with local authorities in Sydney, Reuters reported.
"We stand ready to provide consular assistance," a Foreign Office spokeswoman said.
Forensic police were on the way to Cowan Creek where they would try and identify the bodies that have been recovered.
"(There) certainly were people out on boats and on the water which is why if people have seen what occurred please contact marine area command or crime stoppers," Supt Gorman said.
A Sydney Seaplanes spokesman told AAP the aircraft was one of theirs and said they were working with police on the scene.
The Westpac Life Saver Rescue Helicopter found an oil slick and several items of debris on the surface of Cowan Creek, spokesman Stephen Leahy told AAP.
"There appeared to be a silhouette or outline of a small aircraft but it appeared to be submerged in deep water," he said.
"It was certainly too deep for us to access it and that's why the police divers have been called in."
The Australian Transport Safety Bureau has announced it will investigate the incident.
The company, which has been operating for 80 years, provides flights above and around some of Sydney's most popular tourist sites including the Opera House, the Harbour Bridge, Pittwater and the Hawkesbury River region.
Several visiting celebrities have flown on Sydney Seaplanes aircraft including pop stars Ed Sheeran and Sam Smith, tech mogul Bill Gates, comedian Jerry Seinfeld and actor Cuba Gooding Jnr.
- AAP and Reuters