Twenty kangaroos have been mowed down and killed in a shocking act of animal cruelty on the NSW South Coast.

Police believe the kangaroos and joeys were run over by a vehicle between 10.30pm and 11.30pm on Saturday on Dress Circle and Headland Drive, Tura Beach.

Wildlife Information, Rescue and Education Services (WIRES) volunteers are currently caring for three surviving joeys.

Volunteer Janine Green, who is looking after the joeys, said in her 20 years volunteering for the wildlife service she's never seen anything like the massacre.

"It was devastating, gut-wrenching," she told nine.com.au.

WIRES volunteer Janine Green (right) is caring for the animals. (Supplied/Janine Green)

Police knocked on her door about 1am on Sunday to give her one joey to care for. The next day she went out to remove the dead kangaroos from the residential street with a ranger.

"The people that live there, it a residential street, they live among them.

"They were just walking around shaking their heads," Ms Green said.

"WIRES is horrified to hear about the incident that took place in Tura Beach early on Sunday morning," a spokesperson told nine.com.au.

"Wildlife rescue and rehabilitation can be extremely challenging for all involved, especially when animals have been injured in an apparent act of cruelty."

"WIRES would like to thank local police and all concerned members of the community."

Detectives attached to South Coast Police District are currently investigating the circumstances surrounding the incident.

National Parks and Wildlife Service are also investigating.