Mosman Collective has received images of a large bait ball in the Baths on Wednesday at lunchtime.
Both the Baths and the Beach were closed by local authorities until further notice.
Another eyewitness, wishing to remain anonymous, saw two sharks measuring 1.5m and 1m.
“I would like to know how they found their way inside the netted area,” he told Mosman Collective.
“A few blokes reckon they got in through the gap between the top of the net and the jetty boardwalk at high tide.”
Peter told Mosman Collective he was preparing for his morning swim around 10:30am when a passerby advised him not to enter the water.
“I saw the shark with my own eyes,” he said.
“The water was especially clear this morning, and the sun made it easy to see the bottom.
“I estimate the shark was 1m – 1.5m, but I couldn’t tell what kind it was – or how it got there!”
A diver searches for two sharks that found their way into Balmoral Baths on Wednesday morning.
A Mosman council spokesperson said a specialist diver has inspected the area in and around the baths for signs of sharks.
“Warning signs have also been placed on the shore and barricades placed in front of the baths to alert members of the public,” the spokesperson said.
“Nets in the area were inspected in the past month as part of routine maintenance.
“Further inspections will take place once the water quality improves, as it is presently murky.