Sydney's famous Manly Beach has been closed after a man was injured in a suspected shark attack during an early-morning swim.
The local - believed to be Peter Schultz - was swimming with friends at the adjoining Shelly Beach about 6am on Tuesday when he thought he was bitten.
Mr Schultz, who is a member of Manly's Bold and Beautiful swim squad but wasn't swimming with them at the time, managed to reach nearby rocks and raise the alarm.
The man, who is a believed to be in his mid-50s, was treated by paramedics for a puncture wound to his back and injuries to his leg and stomach.
He was taken to Royal North Shore Hospital where he remains in a stable condition.
NSW Police say no shark has been sighted and Surf Life Saving NSW has deployed a drone to search and monitor the area, a spokesman told AAP.
Manly Beach and Shelly Beach have also been temporarily closed, he said.
The NSW Department of Primary Industries has been contacted to determine how the man was injured.
Danny Lucas, who was also swimming, said two of his friends heard someone calling out and saw the man on the footpath.
"There was a reasonable amount of blood on the footpath and there were a number of passers-by who were looking after him and calling the ambulance," he told the ABC.
"He (Mr Schultz) was very lucid and kept a good sense of humour, we were chatting to him."