Eurobodalla Shire Council has advised South Broulee, North Broulee and North Head Moruya beaches have been closed until further notice.
3.40PM UPDATE: Westpac Lifesaver 3 is reporting two 3.5 metre sharks are off South Broulee beach, which is closed. No swimmers are in the water.
The helicopter has now returned to base.
The beach was closed earlier today after a massive shark attacked and killed a juvenile whale.
The young humpback was spotted, washed onto rocks at South Broulee beach.
A rescue mission was being organised when the whale washed back off the rocks and was taken by the shark.
Two 3.5 metre sharks sighted off Sth Broulee Beach by Lifesaver 3. Beaches closed nearby, no swimmers in danger. pic.twitter.com/8FMiisaV16— Westpac Life Saver (@Lifesaverhelo) January 7, 2015
3.15PM UPDATE: Experts from ORRCA - Marine Mammal Rescue and Research - Australia are now on the scene, along with representatives of the Marine Park Authority.
A National Parks and Wildlife Service spokesman has confirmed the whale taken by a shark was a sub-adult humpback whale.
"They grow very quickly from birth (3m) to 8-10m within about two years," he said.
"This one looks in very poor condition which is very likely the reason it beached. The sharks are just doing what sharks do. They are sometimes called the garbage men of the sea – they help keep the oceans clean by consuming carcasses of dead animals."
3.05PM UPDATE: The Westpac Lifesaver 3 helicopter is now airborne and headed for Broulee.
Spokesman Stephen Leahy said surf lifesavers and police were becoming concerned about the large school of sharks feeding on the whale carcass at South Broulee.
2.30PM: A NSW South Coast beach is likely to remain closed Wednesday afternoon after a massive shark attacked and killed a juvenile whale.
The whale - believed to be a young humpback - was spotted earlier in the day, washed onto rocks at South Broulee beach.
A rescue mission was being organised when the whale washed back off the rocks.
"Twenty minutes later a massive shark came in and just took half of it," Far South Coast director of surf lifesaving Andrew Edmunds said.
"The beach is now closed and is likely to remain so for the rest of the afternoon. We are advising people to be cautious and stay away from the water."
More than 200 people were on the rocks at the time.
"They have been moved on and police are trying to keep people away from the area."