The stunning yacht where a man and woman were found dead overnight was a $300,000 luxury vessel which had raced competitively up Australia's east coast.
The lifeless bodies of the couple - aged in their early 60s - were discovered inside the 15m-long Taloha when NSW Water Police boarded around 9pm on Wednesday.
The family boat, previously owned by a couple from Church Point on the northern beaches, was moored at Tunks Park marina, Cammeray, on Sydney's north shore.
The couple are understood to have told friends they would be spending Monday night on board the boat, but the alarm was raised when they failed to return.
New details are now emerging about the couple, who arrived in two separate cars at the boat ramp which is adjacent to a busy park on Middle Harbour.
It's now feared they may have lain dead on board for days before their bodies were found.
Firefighters initially entered the yacht wearing breathing equipment over concerns of noxious gases on board the vessel.
A man who asked not to be named, rushed to the scene fearing the couple were his friends.
Sydney Water Police and Fire and Rescue officers at the scene where the bodies of a couple were found on a luxury yacht on Thursday, three days after they were last seen by loved ones
The 47-foot yacht Taloha was onsold in 2022, and had previously belonged to a Church Point couple, then become a family boat and also a racing yacht along the Eastern Seaboard
'I have two friends who match that description who are doing renovations and were camping on board their yacht overnight,' the man said, the Daily Telegraph reported.
Police said at a media conference on Thursday lunchtime that the dead male was the owner of the boat but the cause of death was 'not obvious' ahead of post mortem examinations.
Detective Inspector Siobhan Munro said police are still probing if 'foul play was involved' in the 'hours-old' investigation.
'Nothing has been discounted at this time,' she said.
Police know the identities of the dead couple who are from Sydney, but not the immediate local area where the yacht was moored.
But they are yet to release their names while investigations continue, and detectives canvass the neighbourhood and nearby north shore marinas.
The yacht features three cabins and ensuite, mahogany fittings and a stone bench galley, and had raced competitively from Newport to Airlie Beach in Queensland.
It's believed to have last been sold in 2022, and the annual registration on the vessel was renewed only four weeks ago.
According to one boating expert with personal knowledge of Taloha, the concern over fumes suggests either a gas leak from the galley's cooking equipment, or carbon monoxide from the engine or a heater.
Inside the mahogany-lined luxury yacht Taloha where the bodies of a couple in their fifties or sixties were found on Thursday morning after they did not return home on Tuesday
Emergency services were called to a mooring at Tunks Park last night due to concerns for the welfare of two people believed to be on the 47ft yacht (pictured emergency services at the scene)
When police arrived and boarded Taloha (above, the crime scene on Thursday), they found the bodies of a man and a woman aged in their 60s
'Each vessel requires a gas certificate which needs to be renewed every 10 years,' he said.
'(A gas leak) is not unheard of. It has happened before and [especially] if the boat was completely closed up because it was cold. What a terrible tragedy.'
A number of items identified on the boat were taken away by police for forensic examination as the two bodies were seen being stretchered off the vessel.
A post-mortem examination will be conducted in the coming days to confirm the identity of the man and woman and to determine the cause of death.
Anyone with information about the incident is urged to contact Crime Stoppers on 1800 333 000.