Circumcision may help protect gay men from contracting the virus that causes HIV/AIDS, researchers in Australia have found.

"We've shown for the first time that men who predominantly take on the insertive role in sex are less likely to contract HIV if they've been circumcised," David Templeton, from the University of New South Wales, told an international gathering in Perth.

The Sydney-based researcher said his team studied 1,426 HIV-negative men, two-thirds of whom were circumcised, and tracked their HIV infection over four years.

While circumcision did not reduce the HIV risk overall, the study found men who predominantly took the insertive role had an 85-per-cent reduced risk of contracting HIV if they were circumcised.

Templeton warned against any notion that circumcision provided protection, noting that most HIV infections were contracted in the receptive role, not the insertive role.

Circumcision provides some protection because it removes the foreskin which is prone to lesions, which in allow the virus to enter the body through the penis.