Demand for organs such as kidneys is soaring in all Western countries because more patients are suffering kidney failure and the supply of organs is diminishing. An estimated 40,000 patients are waiting for a transplant in western Europe, more than 6,000 of them in the UK, and 15 to 30 per cent will die on the waiting list. In the British Medical Journal, Amy Friedman, associate professor of surgery at Yale University School of Medicine, says: "The demand for life-saving organ transplantation has so outpaced supply that waiting patients and transplant teams are desperate.

"Improved survival rates coupled with steady expansion of indications for transplantation make the organ shortage progressively severe. Waiting times are now unbearably long."

The average wait for an organ in Europe is three years and by 2010 it will have increased to 10 years, a report by the parliamentary assembly of the Council of Europe said in 2003.

International crime syndicates are cashing in on the shortage, drawn by the high profits that can be made from trafficking in human organs. Young people in eastern Europe can earn $3,000 (£1,500) for a kidney and the patients receiving them pay up to $200,000 (£100,000) for a transplant.

Professors Friedman's call has been echoed by other specialists. In Britain, Professor Nadey Hakim, transplant surgeon at St Mary's Hospital, London, has said the black market in organs can no longer be ignored, and the risks of the unregulated trade in organs outweighed the dangers of legalising it.

"As this trade is going on anyway, why not have a controlled trade where if someone wants to donate a kidney for a particular price, that would be acceptable? If it is done safely, the donor will not suffer."

Sir Peter Bell, professor of surgery at the University of Leicester, suggested "compensatory payments" should be made to relatives who donated the kidney of a family member, as a way of staving off the growing trade in organs from the developing world.

Kidney patients are known to have travelled abroad from Britain, mainly to India, to buy replacement organs. A survey from Queen Elizabeth Hospital, Birmingham, in 2002, found 29 NHS patients who had bought kidneys, half of which failed. A third of the patients had died.

Sir Graeme Catto, a kidney specialist and president of the General Medical Council, which defines the ethical standards governing medicine, has called for a debate. He said the desperation of dying patients whose only hope was to obtain an organ, legally or illegally, was driving the trade and demanded attention.

Professor Stephen Wigmore, chairman of the British Transplantation Society Ethics Committee, said: "People who are the most financially disadvantaged will be the donors, and there is little evidence to suggest financial reward to paid organ donors produces long-term benefit in terms of change of lifestyle."

Professor Friedman says in the BMJ that paying donors for certain body tissues, such as blood, semen and eggs is already practised in the US. Volunteers are also paid to take part in drug trials or to act as surrogate mothers. Regulating the system, which could be overseen by a national body, would also help prevent a black market in organs.

"At the moment, kidneys are covertly transplanted in Third World countries, from indigent donors into wealthy recipients. Bringing these activities out of the closet by introducing governmental supervision and funding will provide equity for the poor, who will get equal access to such transplants.

"It is appropriate that living donors, indigent or wealthy, share in the tangible benefits of their ethical concern for others. Not doing so, effectively restricting the disadvantaged, is unreasonably disingenuous."

Rules around the world

UK

It is not automatically assumed that every person is an organ donor.

To be an organ donor, UK residents can join the NHS Organ Donor Register, carry a donor card, pictured, or make their family aware of their wishes.

In the UK, when a registered donor dies, their family is still then asked for consent before organs are removed.

AUSTRALIA

It is not automatically assumed that every person is an organ donor.

Australia has the lowest rate of organ donation in the Western world.

To improve the level of organ donation, the Australian Government sent a legally valid consent form to every household in the nation in 2005.

SPAIN

It is automatically assumed that every person is an organ donor. In Spain, the families of potential donors are permitted to refuse consent. This is the soft opt-out system.

AUSTRIA

It is automatically assumed that every person is an organ donor.

The views of families of potential donors are not taken into account. This is an example of the hard opt-out system.

UNITED STATES

Families of potential donors must be asked about the possibility of donation. It is illegal to disconnect a ventilator from a patient declared dead without making inquiries about donation. Wisconsin was the first state to give living donors a tax deduction of up to $10,000 to cover expenses.

IRAN

The sale of kidneys in Iran is legal and regulated. US$5000 - $6,000 is an average price.

CHINA

British transplant surgeons have accused China of abusing its high rate of capital punishment by harvesting organs from executed prisoners without consent.

MOLDOVA

International adoption has been made illegal because of fears of organ trafficking and the adoption of children for this purpose.

Jeremy Clarke