At least 15,000 human kidneys a year are sold and obtained through organ trafficking and many medical professionals are turning a blind eye (and hand) on the practice.

At a United Nations Forum in Vienna, Austria, University of Berkeley Professor Nancy Scheper-Hughes accused surgeons and top medical professionals of being in league with criminal elements in targeting desperate transplant patients.

"It (organ trafficking) involves people from the highest level of their profession. Some surgeons are "willing to collaborate with the lowest levels of society - with criminal networks, brokers and with kidney hunters, who are the absolutely necessary factor," said the medical anthropologist.

Scheper-Hughes is the founding director of Organs Watch, task force of social scientists and transplant surgeons who have launched a global investigation on organ trafficking -- the finding and selling of human body parts for transplantation.

Organs Watch collects anthropological evidence, which the group hopes, will, through publication in scholarly journals, help protect the world's poor from human rights abuses.

"I call it neo-cannibalism," said Scheper-Hughes, "the notion that we can eye each other greedily as a source of spare body parts."

Organ trafficking has been denounced by all international medical and human rights groups, she said. Still, there is little surveillance over what is increasingly a black market where both doctors and the so-called "body mafia" serve as organ brokers.

In South Africa, Scheper-Hughes said she has witnessed the cadavers of poor, mostly black, victims of violence being "looted" for usable eyes and heart valves. In Brazil, the government declares everyone a universal organ donor at birth, she added, and people in poverty are terrified of becoming fodder for the organ trade.

Trafficking doesn't have to be transnational and can also be found within countries, Scheper-Hughes said.

"The exchanges tend to be poor-to-rich," she explained, citing as an example that at the black market in India, an impoverished person's kidney, destined for an affluent customer can fetch $1,000 to $2,500.

A conservative estimate for the number of trafficked kidneys would be 15,000 each year, but the professor stressed that there is no way of telling exactly how many people are victimized each year.

"Most victims of kidney trafficking are coerced by need, not by physical force. It's driven by desperation," Scheper-Hughes said.

According to the World Health Organization, the shortage of an indigenous supply of organs has led to the development of the international organ trade.