Puzzled police are trying to glean how two people ended up dead with no signs of serious injuries on a yacht moored off Sydney’s well-heeled north shore.

The bodies of a man and woman, both believed to be in their 50s or 60s, were found on the 47-foot yacht near Tunks Park at Cammeray on Wednesday night.

A concerned friend of the duo had called emergency services and asked for a welfare check on the pair.

Fire and Rescue NSW personnel were called in after fumes were detected on board and a number of items were taken off the boat, but police had little other information to work with by early Thursday afternoon.

The duo are believed to have left on the boat, named Taloha, on Monday before being discovered dead at 9pm on Wednesday.

“Detectives are currently walking up and down the marinas and talking to people as we speak … because in a matter like this, we don’t know what has happened,” Detective Inspector Siobhan Munro said.

“We’re treating it as suspicious, purely because the matter and cause of death is unknown, but there’s no indication at this stage that, for example, it was domestic violence-related or anything like that.”

Police did not yet know how the pair knew each other or when they died, Munro said.

Cars belonging to each of the deceased were found nearby and towed away by police.

The dead man was the owner of the boat.

A crime scene was established in the area and the bodies were removed from the vessel on Thursday.

Munro said no information had been uncovered so far that would indicate any members of the public should be concerned for their safety.

“Obviously, that will be our immediate concern as to what exactly has happened, and if there is anything identified mechanically that needs to get out to the public. We’ll make sure that that is done as soon as possible,” she said.

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