As part of an international research project, a team of scientists from the Queensland Institute of Medical Research studied the genes of almost 6000 people together with their mole count.

Queensland Institute of Medical Research Professor Nick Hayward said his team discovered two genes that increased melanoma risk by influencing the number of moles a person had.

In a follow-up study of a further 4000 people, the researchers went on to show the same two genes also increased the risk of moles developing into melanoma the deadliest form of skin cancer.

''It has long been known that having a large number of moles is the biggest risk factor,'' Professor Hayward said. ''Therefore we predicted we would find genes linking moles and melanoma.

''We now have conclusive genetic evidence that having a large number of moles increases an individual's risk of developing melanoma.''

The study found that people who carried one of the two gene variants from one parent had a 25per cent greater chance of developing melanoma, while individuals who carried variants from both parents had double the risk.

Professor Hayward said the research would help develop screening techniques and ultimately allow scientists to develop new therapies.

Australia has the highest incidence of melanoma in the world, with more than 10,000 new cases and 1000 people dying from the disease every year. AAP