At first they are just a blur, tiny figures by a river in Peru's Amazon jungle. Then the plane descends, the camera focuses, and you see them: 21 people outside palm huts, the apparent remnants of an uncontacted tribe. They gaze up at the intruder, itself a blur of noise and metal, and a woman carrying arrows gestures aggressively. When the plane makes a second pass the people melt into the jungle.
The encounter took place last month by the banks of the Las Piedras river in the Alto PurÃƒÂºs national park near Peru's frontier with Brazil. Scientists believe the grainy figures were members of the Mascho Piro tribe, hunter-gatherers who have shunned the outside world.The contact was fleeting but the repercussions could be profound because this swath of Amazon, 550 miles east of Lima, is at the centre of a battle pitting indigenous rights groups and environmentalists against the Peruvian state, loggers and oil companies.
Those who want to develop the rainforest have played down the impact on its human inhabitants. Some even questioned their existence. Daniel Saba, president of Perupetro, the state oil company, said the notion of uncontacted tribes was "absurd" since no one has seen them. A company spokesman compared the rumours to the Loch Ness monster.
The film, taken by ecologists from the national institute of natural resources, is a powerful riposte.
They were looking for evidence of illegal logging and spotted the group by chance, said Ricardo Hon, a forest scientist who was in the small plane. "There were three huts and about 21 Indians - children, women and young people," he said.
Similar types of huts were spotted in the region in the 1980s, prompting speculation that this was the Mascho Piro, a tribe which erects temporary dwellings near riverbanks during the dry season when it is easier to fish, then move back into the forest during the wet season.
"This is the most recent recorded sighting of them," said Peru's national Indian organisation, Aidesep. "The uncontacted tribes exist. If we don't act now, tomorrow could be too late."
Contact with outsiders has proved fatal to people who have not developed resistance to the common cold and other illnesses. More than half of the Murunahua tribe who came into contact with loggers in the mid 1990s are said to have died. Some members of the Mascho Piro, estimated to number about 600, are believed to have had dealings with more settled groups but most have avoided the outside world>
Convention on International Trade in Endangered Species (Cites)
IFAW - the international fund for animal welfare
IUCN - the world conservation union
Joint Nature Conservation Committee
Marine Conservation Society
WWF UK: endangered species
© 2007 The Guardian