SYDNEY, Australia - Australia announced Thursday it will lift a 5-year ban on clinical trials of animal-to-human transplantation, after the government's top health body determined the risk of transmitting animal viruses to people was low.

The decision by the National Health and Medical Research Council means Australia will join a slew of other countries - including the United States and New Zealand - who have conducted trials of xenotransplantation, the transfer of living cells, tissues or organs from one species to another.

Xenotransplantation researchers hope the procedure can someday serve as a substitute for human organs, which are in chronic short supply, and help treat diseases such as diabetes and Parkinson's.

The council issued a ban on clinical trials in 2004, after concerns were raised about the risks of transmitting animal viruses - particularly those from pigs - to humans.

On Thursday, the council said in a statement it was satisfied such a risk was low and that trials should be allowed to proceed once strict regulatory and surveillance frameworks are put in place. The council plans to consult the Australian Health Ethics Committee and Animal Welfare Committee to develop guidance for researchers and ethics committees involved in animal-to-human studies.

The World Health Organization has urged nations to establish regulatory control and surveillance mechanisms before allowing such transplants to take place.

"After careful consideration, the Council is of the view that, although there is a wide range of community views on the topic, xenotransplantation research was acceptable in Australia when there are robust regulations in place," council Chairman Michael Good said in a statement. "Council has taken into account a range of issues including the risk of viral transmission and the evidence available on the safety of the therapy for individuals and the wider community."

The move was welcomed by Australian biotech company Living Cell Technologies, which is conducting a trial in New Zealand that implants cells from newborn pigs into human volunteers as an experimental treatment for their diabetes.

The cells produce pig insulin, which is very similar to human insulin and has the same effect of lowering blood sugar, and Living Cell Technologies hopes the cells may be able to delay the effects of Type 1 diabetes - including blindness, premature coronary illness and limb amputation caused by poor blood circulation.

The company is now considering expanding its clinical trial program to Australia, CEO Paul Tan told The Associated Press.

"What the lifting of the moratorium tells us is that the NHMRC has reviewed the information and has come to the conclusion that the accumulated scientific data over the last few years have given them the assurance that some of the concerns in the past were unfounded," he said.

Much of the concern over cross-species virus transmission surrounds pig endogenous retrovirus - the porcine virus thought to be most contagious for humans. Tan said advances in science have ensured that pigs can be bred in such a way that they do not transfer the virus.

But Jacqueline Dalziell, project co-ordinator for Animal Liberation, a group opposed to the use of animals in scientific testing, is not convinced the procedure is safe.

"The public, who had no say in this discussion whatsoever, will be the first to be directly affected if a new pandemic like AIDS ... is introduced into Australia through the ban being lifted," she said. "The whole of Australia is currently taking part in an experiment without their consent."