A 12-year-old boy remains in the fight of his life after being mauled by a suspected bull shark in Sydney Harbour and heroically rescued by his friends.

The boy was jumping off a rock face at Neilson Park near Shark Beach in Vaucluse yesterday when he was attacked by what police believe was a bull shark.

NSW Police Superintendent Joe McNulty said the boy was bitten as soon as he was in the water.

Paramedics had to revive the boy when he was taken ashore.© Nine

One of his friends jumped into the water to rescue him, while two others pulled the pair ashore.

The boy suffered serious injuries to both of his legs.

“It was very confronting injuries for those boys to see, but I suppose that’s mateship,” McNulty said.

Maritime police arrived just minutes later, applying tourniquets to the boy’s legs and conducting CPR.

NSW Ambulance Inspector Giles Buchanan said the tourniquets were “definitely a lifesaving intervention”.

“It was touch and go the entire time, and still he’s in a very dangerous position,” he said.

McNulty said it was a “textbook recovery” to give the boy a “fighting chance for survival”

“He’s in for the fight of his life now, and the actions of emergency services yesterday gave him that chance.”

The quick thinking of emergency services and one of the boy’s friends helped save his life.© Nine

The boy was resuscitated and rushed to Sydney Children’s Hospital in Randwick, where he underwent surgery.

He remains in intensive care tonight, with the next 24 hours crucial for his recovery.

Neilson Park remains closed today.

Premier Chris Minns said it was a “terrible, terrible incident”.

In the hours before the attack, Sydney was hit by a storm, heavy rain and runoff, which made the water murky.

The sun only came out yesterday afternoon, around the same time the boys went for a swim.

“We believe the combination of the brackish water, the fresh water, the actions of the splashing, may have made that perfect storm environment for that shark attack yesterday,” McNulty said.

The Department of Primary Industries said a bull shark was likely responsible for the attack.

Superintendent Joseph McNulty said the work of paramedics was© Nine

Bull sharks are known to frequent Sydney Harbour, particularly during the warmer months of January and February.

Experts say they can be found right across the harbour and come to the shallow parts of the water at dusk and dawn.

The last shark attack in Sydney Harbour was in 2024 when swimmer Lauren O’Neill was bitten in the leg by a bull shark at Elizabeth Bay and survived.