Millions of people living around the northern Bay of Bengal face the threat of a giant tsunami as devastating as the one in 2004, an Australian scientist has claimed.

There has been concern about the likelihood of another large earthquake off central Sumatra, just east of where the 2004 temblor struck triggering the Indian Ocean tsunami almost three years ago.

However, Phil Cummins, a senior seismologist at Geoscience Australia, has now found "compelling evidence" of a potential tsunami risk in the northern Bay of Bengal, particularly along the coasts of Burma and Bangladesh.

More than 60 million people live within 10 metres of sea level at the bay's northern tip, he said, and heavily populated towns such as Chittagong, Dhaka and Kolkata could also be affected.

His findings, published in Nature today, are based on a review of geological data, combined with a study of precise measurements of movements in the Earth's surface.

This work suggested that the boundary between tectonic plates near the Burmese coast was much more active than previously thought.

The movements of the plates were consistent with a so-called "locked-thrust" fault, the kind needed to generate tsunamis, but may have been masked by a 20-kilometre thick layer of sediment known as the Bengal Fan.

Cummins said it may be more than 200 years before the next giant earthquake strikes. And while smaller events could occur earlier, "the risk of a major tsunami in the northern Bay of Bengal should be taken seriously".

He warned against panic or the introduction of any "drastic mitigation measures", but hoped his study would lead to further research into the potential risk.