SIX PEOPLE have died after a sightseeing seaplane crashed during a 'wine and dine' flight in Sydney.
All five passengers and the pilot of the seaplane died when it crashed into the water in Hawkesbury River about 3:15pm.
Police divers have recovered the bodies from the submerged wreckage.
Aaron Shaw, the managing director of Sydney Seaplanes, confirmed one pilot and five passengers were on board.
The seaplane was returning a party of five people from the Cottage Point Inn Restaurant to Rose Bay in Sydney's east when it crashed into the water, immediately sinking.
Police said they did not know the cause of the crash, or 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.
It's believed four of the victims were British nationals, although that was not immediately confirmed by police.
An 11-year-old boy is also thought to be amongst the dead.
In London, the Foreign Office said its officials were in contact with local authorities in Sydney.
"We stand ready to provide consular assistance," a spokeswoman said.
"We have spoken to a number of witnesses," Acting Superintendent Michael Gorman told reporters, adding that forensic police would inspect the plane to assess when it could be raised from the seabed.
"It's too early in the investigation so we don't know why the plane crashed."
Mr Gorman said police were liaising with Sydney Seaplanes to identify the victims and their families would be contacted before they were named publicly.