Some 2,500 naked volunteers have posed in the early morning light on Sydney's Bondi Beach for an artwork designed to raise awareness of skin cancer.

The installation is American photographer Spencer Tunick's latest project, aimed at encouraging Australians to get regular skin checks.

Legislation was changed to allow public nudity on the beach for the first time.

Australia is the country in the world worst affected by skin cancer, the World Cancer Research Fund says.

From 3:30 local time, volunteers gathered on the beach to take part in the installation, done in collaboration with the charity Skin Check Champions during skin cancer awareness week.

"We have an opportunity to raise awareness about skin checks and I'm honoured... to come here, make my art and just celebrate the body and protection," world-renowned artist Tunick said in quotes cited by Reuters.

Bruce Fisher, 77, who participated in the event, told AFP: "I've spent half my life in the sun and had a couple of malignant melanomas taken off my back.

"I thought this was a good cause and I love taking my clothes off on Bondi beach."

Tunick is well-known for masterminding images of mass nudes in some of the world's most iconic locations.