An investigation has been launched into the circumstances surrounding the death of a man after his body was discovered on a yacht.

Sydney Water Police officers performed a welfare check at 5.45pm on September 28 after a report raised concerns for the safety of the man aboard the vessel, NSW Police confirmed.

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The man, believed to be in his 60s, was found on Sydney Harbour, near the ferry terminal for Taronga Zoo, police said.

The yacht was boarded by police at Little Sirius Point near Cremorne Point, investigators said.

"Police on scene located the body of a man, believed to be aged in his 60s, in the boat," police said.

Detectives are investigating the circumstances surrounding the death.

Investigators will prepare a re

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