A government decision to scrap a committee which regulates animal-to-human transplants has drawn condemnation from ethicists who fear there could be a free-for-all in xenotransplantation. But the government insisted last night that the move last month was a response to a lack of interest in research into the transplants after it became clear that the science was not going to provide the answer to the shortages in donor organs.

Xenotransplantation had been seen as a possible solution to the organ shortage, but, as well as ethical fears, there are concerns about how diseases in pigs would mutate in humans into new diseases. The UK Xenotransplantation Interim Regulatory Authority (UKXIRA), was responsible for regulating and advising on the animal-to-human transplants.

Laura Williamson, an ethicist at Glasgow University who has written reports for UKXIRA, said: "There is a risk to public health. Individuals shouldn't be able to consent to procedures which could threaten public health. Xenotransplantation could potentially be so dangerous that people who receive animal organs would have to refrain from having children, refrain from unprotected sex."

A Department for Health spokesperson said: "At the time UKXIRA was established it was thought xenotransplantation could prove to be a potential solution to the shortage of organ transplants. However, research has not developed as it was thought at that time and it doesn't look likely it will offer solutions in the short to medium term.

"The regulation of xenotransplantation has developed considerably and we expect that any xenotransplants that do come though to be dealt with through the clinical trials framework with reviews by Medicines and Healthcare Products Regulatory Agency and a research ethical committee."

There were unlikely to be trials to prove the procedures to be safe as no one would consent to the operation in numbers large enough to assess, but people desperate for a cure when they have a failing organ could consent as a last resort, something witnessed in other countries, she said.

Animal-to-human transplants have taken place abroad but not in the UK; UKXIRA had expressed concern that people desperate for a transplant might be tempted by "xenotourism".