A Queensland team has revealed the detective work which uncovered a crucial link to identifying potential victims of a deadly cancer - before it strikes.

Silently, the killer selects its prey. An efficient assassin, the victim is often unaware of being targeted until it is too late. Some escape but all bear the scars.

Descriptions have been circulated. Citizens have been taught how to protect themselves. Still the death toll rises. And Queensland is the favoured hunting ground.

It is here that scientists are rapidly closing in on deadly melanoma.

Dr Stuart MacGregor is not a stereotypical detective but he knows the value of solid footwork, following clues and gathering evidence under time's relentless pressure.

For more than two years, Dr MacGregor and his team at the Queensland Institute of Medical Research have been painstakingly piecing together the puzzle.

This week they released news of a major lead that brings them one big step closer to identifying likely victims.

For the first time it's been discovered that one in six Australians carries a gene variation that doubles their risk of developing melanoma.

Dr MacGregor said this was the first in the anticipated identification of a number of genetic factors that make people more susceptible to melanoma, which strikes about one in 15 Queenslanders.

"The detective analogy might be apt in that you get a hint that this particular thing could be true, but it's not until you get the corroborating evidence from elsewhere that you really see," he said.

Their first clue came in the initial examination of the DNA of 800 Queenslanders with melanoma and 800 without. Of all the genes, chromosome 20 topped the list as a likely contender to being a pointer to genetic susceptibility.

Excitement grew as its importance was confirmed in an examination of only chromosome 20 in a second sample of another 1600 Queenslanders.

When a third, wider sample of 1000 Australians cemented the finding in January, "that was the point when we thought right, we've really found something - this is going to be important".

Adrenalin kicked in, everything was dropped to focus on recording this breakthrough.

For it's not just a race against time to improve public health. It's also a race to beat other detectives to break the case.

At the same time Dr MacGregor and his team made their breakthrough, another team in Iceland made a similar finding in European populations. The research was published side-by-side in the journal Nature Genetics this week.

Essentially the implication of the joint findings, as Dr MacGregor explains, is that worldwide "wherever you've got enough sunlight to cause melanoma, people who carry these genes will be at increased risk".

Australia _ particularly Queensland _ has the highest incidence of melanoma in the world. By 2011, experts predict more than 11,600 new cases will be diagnosed, compared with only 8900 in 2001. About 10 per cent of cases are fatal.

Dr MacGregor's work from now on will be two-pronged: Pinpoint the exact variants on chromosome 20 and the biology behind them and, second, identify other important genes.

"This part of chromosome 20 is going to be most important but there will almost certainly be other ones which won't be quite as important - but, collectively, will help us describe which people will be at high risk and which people (at) low risk, which is what we want to do to improve public health.

"In time, that will lead to a blood test, which will be able to say, given any individual, 'This person has a certain likelihood of melanoma and this person doesn't'."

From here, public health messages of prevention and early detection can be further targeted to reduce the incidence of, and death toll from, melanoma.

"It is exciting. Because there are so many parts of the puzzle you have to sort out, it means it's always interesting and the added competition means you are that bit keener to make sure you get your work out first," Dr MacGregor said.

"You are hoping, as a scientist, that you will be able to make a difference to things.

"You want to get there first, you want to feel that the science we do here is the best in the world and that we can find new things.

"One of the biggest challenges of the work in science is to understand the human body - and work in genetics is the most exciting there is, in my opinion."