An indigenous tribe in the Amazon jungle has secured the return of blood samples taken from its people by American researchers in the 1960s.
Thousands of samples were taken from members of the Yanomami tribe, in 1967 for genetic testing.
A Yanomami shaman, Davi Kopenawa, said the blood would be buried with special prayers.
He said his people had been horrified to discover it had been kept in freezers far from home for years.
Davi Kopenawa said, "I was 10 or 11, and the non-Indians [American scientists] came to our community. We had four different villages there who lived with a lot of missionaries. The missionaries told the village elders that we had to give blood."
In return, he said, the American scientists gave the Yanomami pots, pans, fishing hooks, rope, matches and knives.
"An [American] anthropologist talked to us about the blood, this blood that they should not have taken and we should not have let them take. That is how I remember it," Mr Kopenawa added.
He and a representative of Yanomami communities across the border in Venezuela went to the United States to talk to the American anthropologists to ask for the return of the blood.
He spent years pushing for the return of the samples.
Eventually, in May 2010 five research centres in the United States which had kept Yanomami blood for decades agreed to a proposal by the Brazilian government to return the blood to the tribe.
Mr Kopenawa said the scientists had not specified how the blood was used at the time.
"The white man tricked us so that they could take it away," he said. "The blood belongs to our people. We have the right to have it back."
The researchers, led by geneticist James Neel and anthropologist Napoleon Chagnon had been doing research to see if the Yanomami were direct descendants of the first people to cross the Bering Strait from Asia into the Americas thousands of years ago.
According to Survival International, when a Yanomami dies, the body is cremated and it is essential no physical remains or possessions of the dead are kept.
The Yanomami believe this is so that the dead person can depart and separate the world of the living from the world of the dead.
Mr Kopenawa said the blood would be taken to Yanomami territory on Friday to one of the villages where it was extracted in northern Brazil for a special ritual with other religious leaders and for prayers to mark its return.