The unidentified woman, believed to be aged between 20 and 35 and of Asian appearance, was seen floating face down near the blow hole adjacent to Snapper Point, in the Lake Munmorah State Conservation Area, on Sunday morning.

Emergency service personnel immediately suspected she had become another victim of the fishing graveyard, where 18 people have drowned in eight years along a three-kilometre stretch south of Catherine Hill Bay.

But when her body was recovered, it was quickly discovered she had suffered a much more sinister fate.

Fairfax Media understands the woman appears to have suffered stab wounds.

Homicide squad Detective Inspector Gary Jubelin would not be drawn on the injuries and said investigators would wait for a full autopsy report.

Detective Inspector Jubelin said the body may have been in the water for "a couple of days" and pleaded with anyone who had visited the park in recent days to call police.

The woman, who had not been identified on Sunday night, was described as being of Asian appearance, aged between 20 and 35 and approximately 170cm tall.

"We would be very interested in speaking with anyone who has any concerns about someone who matches that description," Detective Inspector Jubelin said.

The bizarre case began when the woman's body was seen floating face down in the blowhole next to Frazer Park about 10.30am on Sunday.

With large seas crashing against the notoriously dangerous rock shelf, the Hunter Westpac rescue helicopter was called in to retrieve the body.

It was after the body was taken away that suspicions began to be raised about what occurred to the woman.

The place where she had been recovered had taken the lives of 16 fishermen in eight years and prompted several coronial investigations.

But by noon, Tuggerah Lakes officers had been joined at the site by specialist police as the investigation got into full swing.

Officers spent most of the day at the site gathering evidence.

The Sydney-based homicide squad travelled to the area to assist Tuggerah Lakes detectives with the murder investigation.

They were still working on identifying the woman on Sunday night.