A legalised and regulated system for paying people to donate organs should be created to help answer the large demand for transplants and prevent exploitation of poor people, says an article in this week's BMJ.

The author an organ transplant surgeon has written an opinion piece arguing for payments to be made for live organ donation, saying it does not go against current ethical practice in healthcare and would help with the "desperate" need for organs.

Many people who agree to participate in medical research do so for financial reward, points out the author Amy Friedman, associate professor of surgery at Yale University School of Medicine in the USA.

"If it is reasonable, legal, and ethically justified to motivate someone using monetary reward to participate in human research, then by extension the same person should be allowed a monetary inducement or reward for donating an organ," writes Professor Friedman.

The buying and selling of regenerative products such as human hair, blood and semen occurs and human eggs are now sought openly with a price offered for them payment is legal in the USA.

Professor Friedman says proper supervision of a transplant process would minimise potential medical and surgical harm and might be accomplished through a centralised, multi-disciplinary panel with responsibility for determining standardised criteria for donors and recipients as well as a uniform fee.

Kidneys are covertly transplanted in third world countries at the moment from poorer people to wealthier recipients, she says, with little evidence of the outcomes.

"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."