could soon be broken up after a decision to return the bones of 17 Aboriginals in the collection to Tasmania.

The Natural History Museum in London announced this weekend that it has decided to set a precedent by giving the remains to a Tasmanian Aboriginal group which intends to cremate them in a funeral ceremony. Experts in anthropology criticised the decision, which was taken after the law was changed to allow human remains in the national collection to be sent back to their country of origin.

Professor Chris Stringer, the head of human origins at the Natural History Museum, whose board of trustees took the decision, said: "This is an important population in terms of human history. If the material goes back and is cremated it will be a loss for scientists and a loss for future generations of Tasmanians." But Michael Dixon, the director of the museum, defended the decision on the grounds that the scientific value of the material did not trump all the claims on it by any descendants. "We acknowledge our decision may be questioned by community groups or by some scientists, " he said. "However, we believe the decision to return the Tasmanian remains, following a short period of data collection, is a common sense one that balances the requirements of all those with an interest in the remains."

The museum holds 19,950 specimens of human remains, which vary from complete skeletons to a single finger bone. The specimens span 500,000 years and about 44% of them come from outside Britain.

Dixon said other claims could soon be made by native groups in America and New Zealand. "We're in discussions with the Australian government for the return of all Australian remains, " he added.

There are 24 sets of humans remains from the 17 Tasmanian Aboriginals, which were collected in the 18th and 19th century and eventually donated to the museum. At the time of collection it was common for the bodies of paupers, executed murderers and workhouse inmates to be "donated" to medical science or the wealthy curious.

The Tasmanian Aboriginal Centre claimed that the remains were not given with full informed consent and therefore demanded their return under legislation that came into force last year. Professor Richard Lane, the museum's science director, said the trustees were convinced that the Tasmanian group had a legitimate claim.

Only one of the Tasmanian specimens can be potentially identified as a named individual and some commentators have argued that the decision to return them is weakened by the fact that no direct line of descent can be established with Aboriginals living in Tasmania today. The museum is committed to returning the specimens within three months but intends to perform more sophisticated, nondestructive, tests, including DNA analysis, before the bones are sent back. The Tasmanians had objected to any further scientific study of the bones but their objections were overruled.

Stringer said that destroying the material means that the bones will never be available for further study when new forensic techniques are invented.

"Who would have thought a few decades ago that we would be able to get DNA from Neanderthal bone?" he said.

Professor Robert Foley, a human evolution expert at Cambridge University, said: "There is no doubt that if these remains are destroyed, our knowledge of our humanity will be diminished."