A passer-by made the grim discovery in sand dunes just south of The Avenue about 4.40pm.

Victoria Police spokeswoman Kendra Jackson said at this stage the death was not being being treated as suspicious.

She said the man's identity was yet to be established.

It is believed his body may have been in the sand for a number of days and was dressed in a suit.

Ambulance Victoria spokesman John Mullen said paramedics treated a woman who suffered a seizure at the scene.

"She was a bystander down there," he said.

"She had a seizure so she was treated and transported to hospital in a stable condition."

 Police will prepare a report for the coroner.