The morning is dry and cold in the Argentine woodlands but Apolinario Dominguez is bent on taking off his shirt to allow visitors to see his emaciated skeleton – all 36kg (six stone) of it – for themselves. With a claw-like hand, he grabs his ribs; the flesh has all but melted away and his fingertips are almost touching. But his eyes sparkle from their sunken orbits for today is a good day – after almost 100 hours without a bite to eat, he has managed to put a meagre amount of food in his belly.

Apolinario belongs to the Toba tribe and his plight is repeated among the 30,000-strong aboriginal population all over this densely forested area of Chaco province, otherwise known as El Impenetrable. Their suffering has burst into the national consciousness, after the deaths of 14 Toba in recent weeks from a combination of malnourishment, tuberculosis, and the Chagas virus, carried by the local vinchucas bugs.

Key to the tribe's decline, according to a human rights group that monitors the area, is the indiscriminate and sometimes illegal deforestation that is paving the way for more commercial and profitable plantations, in the process destroying the Toba's natural habitat. Apolínario, for example, used to be a bracero, picking cotton. But now it is soya that is taking over. Argentina is already one of the world's largest exporters, feeding the exploding global market for biofuels.

While much of Argentina is enjoying a strong rebound from the financial crash earlier this decade, its aboriginal populations continue to live on the margins with little or no political voice and a standard of living worlds apart from the middle classes of cities such as Buenos Aires.

The Toba have always been reliant on algarrobo trees, but many of have been felled to make way for the soya plantations, depriving the people of the highly nutritious algarroba bean, and driving out the prey they used to hunt with bows and arrows. "El Impenetrable sums up the situation of aborigines in Argentina," said Rolando Nuñez, a solicitor who runs the local Nelson Mandela Centre for Social Research and Human Rights.

"Hunger is growing day by day in the area, and that, added to the constant presence of tuberculosis and Chagas, and lack of medical attention is making this to seem like the mechanism of a silent genocide."

Ricardo Sandoval, a young aborigine activist whose aunt died four weeks ago weighing just four stone, says Argentina has forgotten its aborigines. "Aborigines are condemned as soon as they are born. They are condemned to hunger, to illness, to discrimination ... They are condemned to be forgotten," he said.

Such allegations are swiftly dismissed by Enrique Mayol, Chaco province's health minister. "The situation is not out of control ... [and] regarding the aborigines, we have intensified our work. We are aware of the cases," he said. But some, like Hubert Oswin Arkwright, a local pro-aboriginal activist of British descent, are not convinced and see more sinister motives beyond the way Aborigines are living.

"There is an ongoing extermination of the aborigines in the Chaco ... land is a big issue here," he explained. "They are aware "the whites" [non-Aboriginal Argentinians] are violating their rights. But they are too weak – physically and politically – to protest."

(By Andres Schipani, The Independent, 20/10/2007)