Last year, the Human Tissue Act (2004) came in to force. Although most of the act was not relevant to museums, section 47 deals with human remains in their collections & gives them a right to de-accession these items if they feel it is appropriate.
One of the key reasons behind this act (& the limitations such as the 200 year rule) was negotiations initiated by the Australian government with Britain to allow Aboriginal remains to be returned permanently.
An agreement has just been made by the British Museum to return some cremation ashes to Tasmania. The British Museum has relatively few items that would fall under the Human Tissue Act, but campaigners in Australia hope that these returns will lead to the return of much larger numbers of remains in the collection of Natural History Museum.

From:
Tasmanian Examiner

UK museum will return remains
By LUCIE VAN DEN BERG , Saturday, 25 March 2006

After 21 years of negotiating, the British Museum in London will give back two rare bundles of Tasmanian Aboriginal remains to the State.

The historic decision will result in the return to Tasmanian Aborigines of the precious cremation ashes that were taken from the necks of sick or dead Aborigines in the earlier stages of white settlement. The ashes were traditionally worn on the body of Aborigines in the belief that they would ward off pain, sickness and ill-fortune and are thought to be the last of their kind in existence.

The trustees of the British Museum announced the decision to repatriate the artefacts from a public museum in Britain yesterday.

The journals of George Augustus Robinson detail how the bundles were stolen from the Aborigines and handed to the Royal College of Surgeons in 1882, before being passed on to the British Museum.

Tasmanian Aboriginal Council State secretary Trudi Maluga is overjoyed with the outcome of a battle to reclaim Aboriginal artefacts that was first waged in 1985. “To think that we thought these bundles were gone forever – it’s a really warm feeling that will heal the hurt of the Tasmanian Aboriginal community,” Miss Maluga said.

She said that the decision came from the passing of a new law and fulfilled the joint John Howard and Tony Blair Prime Minister Ministerial Statement of 2000, which supported the return of Aboriginal human remains from all public museums in Britain.

Miss Maluga hopes it will encourage the Natural History Museum in Britain to return skulls and skeletons.

“Now the British Museum has made this landmark action, we look forward on behalf of all Aborigines to the release of all Aboriginal human remains from all British public museums,” she said.