THE South American Indian who took his battle with sugar growers to the world - and became a film star in the process - has been murdered.

Guarani Indian leader Ambrosio Vilhalva was murdered at the weekend as he approached his community, known as Guyra Roká, near the town of Caarapao, in Mato Grosso do Sul state, Brazil.

Vilhalva starred in the 2008 film "Birdwatchers" about his tribe's struggle to return to its ancestral lands. He travelled extensively internationally to speak out about his tribe's plight, and push the Brazilian government live up to its legal obligations and protecting Guarani land.

Initial reports suggest Vilhalva brutal stabbing appears unrelated to recent death-threats from angry ranchers and developers upset at his stance against their rampant and illegal deforestation activities.

Police inspector Benjamin Law said that Vilhalva "stumbled into his home and just before dying he told his wife who his killer was."

Other reports say Vilhalva was found already stabbed to death in his house.

Police arrested the father-in-law, Ricardo Mendes Quevedo, who has denied killing Vilhalva.

The police inspector said he did not know of a motive in the killing but doubted it was related to Vilhalva's efforts for the demarcation of Indian Territory.

A Guarani spokesman told media last night: "Ambrósio fought hard against the sugar cane. He was one of our main leaders, always at the forefront of our struggle, so he was being threatened. He was an extremely important figure in the Guarani land campaign, and now, we've lost him".

Thousands of Guarani-Kaiowa Indians have lived in Mato Grosso do Sul state for years in makeshift camps along highways and tent villages by rivers while lobbying to have their lands legally recognised.

According to the Brazil-based indigenous rights group CIMI, 319 Guarani-Kaiowa Indians were slain from 2003-2012, mostly of them in fights over land with farmers and ranchers encroaching on their land. That's more than half of all 558 Indians killed in the entire country during the same period.

In 2007 Vilhalva's tribe reoccupied part of their ancestral land, though they live on a fraction of their original territory. Most has been cleared for enormous sugar cane plantations - including one owned by a powerful local politician, Jose Teixeira, who is working on a massive bio-fuels project with international oil company Shell.

Vilhalva's struggle to retain his tribe's ancestral lands is not likely to end with his death. "This is what I most hope for: land and justice … We will live on our ancestral land; we will not give up", he recently declared.