AS THE Karitiana Indians remember it, the first researchers to draw their blood came here in the late 1970s, shortly after their Amazon tribe began sustained contact with the outside world. In 1996, another team visited, promising medicine if the Karitiana would give more blood, so they dutifully lined up again.

But those promises were never fulfilled, and since then the world has expanded again for the Karitiana through the arrival of the internet. Now they have been enraged by a simple discovery: their blood and DNA are being sold by a US concern to scientists around the world for $85 a sample.

They want the practice stopped and are demanding compensation for what they describe as the violation of their integrity.

“We were duped, lied to and exploited,” Renato Karitiana, leader of the tribal association, said from the tribe’s reservation in the western Amazon, where 313 Karitiana eke out a living from farming, fishing and hunting.

Antonio Karitiana, the village chief (pictured below) said that health care, sanitation and housing are precarious and transportation deficient. Any money mad from their blood should have been invested “for the benefit of the entire community,” he said.

The Surui people, whose homeland is to the south of the Karitiana, and the Yanomami, who live on the Brazil-Venezuela border, complain of similar experiences.

The indigenous peoples of the Amazon are ideal for certain types of genetic research because they are isolated and close-knit populations, allowing geneticists to construct a more thorough pedigree and to track disease transmission down generations.

But the practice of collecting blood samples has aroused widespread suspicions among Brazilians, who have been zealous about what they call “bio-piracy” ever since rubber seedlings were exported from the Amazon nearly a century ago.

Coriell Cell Repositories, a non-profit entity in New Jersey, stores human genetic material and makes it available for research. It says the samples were obtained legally through a researcher and approved by the National Institutes of Health in the United States.

Joseph Mintzer, executive vice president of the parent organisation, the Coriell Institute for Medical Research, said: “We are not trying to profit from or steal from Brazilians. We have an obligation to respect their civilisation, culture and people, which is why we carefully control the distribution of these cell lines.”

Like a similar centre in France that has also obtained blood and DNA samples of the Karitiana and other Amazon tribes, Coriell says it provides specimens only to scientists who agree not to commercialise the results of their research or to transfer the material to third parties.

The core of the debate has to do with the concept of ‘informed consent’. Scientists argue the appropriate protocols were followed, but the Indians say they were deceived.

“This is sort of a balancing act,” said Judith Greenberg, director of genetics and developmental biology at the National Institute of General Medical Sciences. “We don’t want to do something that makes a whole tribe or people unhappy or angry. On the other hand, the scientific community is using these samples, which were accepted and maintained under perfectly legitimate procedures, for the benefit of mankind.”

But the Indians say that when the first blood samples were drawn, they had little or no understanding of the outside world, let alone the workings of Western medicine and modern capitalist economics.

Francis Black, the first researcher to take samples here, died recently, so it is impossible to obtain his account.

But officials of the National Indian Foundation, the Brazilian government agency that supervises tribal groups, said his presence on the reservation violated procedures specifically designed to protect Indians from outsiders.

in Scotland on Sunday