New genetic evidence suggests Australia may have been populated by two separate groups of humans - one arriving via Papua New Guinea, the other via Indonesia, a researcher says.

But more work is needed to confirm the idea. And not all scientists agree that these latest results shed new light on the long-standing debate on how humans colonised Australia.

Dr Sheila van Holst Pellekaan, a molecular anthropologist from the University of New South Wales in Sydney, will present her research at a Australian Archaeological Association conference in Melbourne next month.