Raimundo Francisco Belmiro dos Santos, a defender of the Amazon jungle, has requested urgent protection from the authorities in Brazil after reporting that a number of hired gunmen are looking for him, because landowners in the northern state of Pará have offered a 50,000 dollar contract for his death.

Belmiro dos Santos is a 46-year-old "seringueiro" or rubber tapper who fears for his life and the lives of his family, after receiving numerous threats for his activism against the destruction of the Amazon jungle.

"My life is really complicated today, because they have put a price on my head, and say that I will be killed before the end of the year," the activist told IPS in an anguished voice by telephone from the Riozinho do Anfrísio reserve, where he lives.

It takes several days to reach the reserve by river from the nearest city, Altamira, which is 800 km from Belém, the capital of the state of Pará.

"I am fighting to defend life, the jungle, nature, and I can't live without protection anymore," Belmiro dos Santos, who is a married father of nine, told IPS.

In response to his cry for help, the prosecutor's service for the state of Pará instructed the police to launch an investigation, sources at the prosecutor's office told IPS.

According to an official statement, prosecutor Cláudio Terre do Amaral ordered the police to ask the Chico Mendes Institute for Biodiversity Conservation (ICMBio) to provide "all documents and information relating to the matter" and for the authorities to provide Belmiro dos Santos with assistance.

The latest threat came on Aug. 7, when an anonymous caller told the activist by telephone: "They are going to the reserve to kill you. If I was you, I wouldn't go back."

But dos Santos says he will continue to return to his home.

Over the last week he has held several meetings with members of the ICMBio, the government agency responsible for managing and enforcing environmental laws in protected areas.

The activist's fears are grounded in a long history of violence in Pará. In May, José Cláudio Ribeiro da Silva and Maria do Espírito Santo, a husband and wife team of activists who spent years fighting illegal deforestation in the rainforest, were gunned down after receiving numerous death threats.

Pará is the Brazilian state with the largest number of murders involving conflicts over land. The Catholic Church's Pastoral Land Commission (CPT), which has documented rural violence in Brazil since the 1980s, has counted hundreds of such killings.

The highest-profile cases included the 2005 murder of 73-year-old U.S.-born Catholic nun and activist Dorothy Stang at the hands of killers hired by local landowners. For four decades she had been active on behalf of the poor in the state of Pará, in Brazil's eastern Amazon jungle region.

Another case that had international repercussions was the April 1996 "massacre of Eldorado de Carajás", in which 19 rural protesters were killed when the police opened fire on a crowd of peasant farmers who were holding a peaceful demonstration on a road in southern Pará.

Environmentalist Marcelo Salazar told IPS that there are many people in the region who dedicate their lives to the tireless struggle to defend the Amazon jungle, and many are murdered "without anyone ever hearing about it."

The threats against Belmiro dos Santos began in 2004, shortly after the government of Luíz Inácio Lula da Silva (2003-2011) declared the creation of the Riozinho do Anfrísio Extractive Reserve, a 736,000-hectare area located in the region of Terra do Meio between the Xingú River and its tributary, the Iriri River, in the southwest portion of the state of Pará.

Extractive reserves are areas in Brazil dedicated to the regulated use of natural resources in such a way that ecological balance is not affected. The idea emerged in the Amazon jungle on the initiative of Chico Mendes, the leader of the "seringueiros" and defender of the environment whose 1988 murder shocked the world.

Belmiro dos Santos was rewarded the government's Human Rights Award in 2004. When the first threats arrived that year, he and his uncle Herculano Porto de Oliveira were flown out of the jungle by helicopter for their own protection and taken to the capital, Brasilia, on the orders of then minister of the environment Marina Silva.

The former minister has now promised, in messages on her Twitter account, to ask the Special Secretariat of Human Rights of the government of left-wing President Dilma Rousseff to provide protection once again.

The destruction of the jungle by landholders, ranchers and loggers has run up against resistance from the Riozinho do Anfrísio Extractive Reserve association, and the name of Belmiro dos Santos, the association's leader, is now circulating among paid killers.

"I have always lived in the jungle," the activist said. "They wanted to buy my small plot of land to get me to leave, but I told them no. I'm not scared of what might happen to me, but I am afraid for the lives of my family, of my children, who live in the reserve," he said, adding that there are some 10 armed men looking for him in the area.

Belmiro dos Santos, who was born and raised in Riozinho, says his grandfather came to the area from the northeast state of Ceará during the rubber boom in the first half of the 20th century.

But when Brazil lost its global market dominance in natural latex, the local population started to shrink, to the current 60 families (around 500 people) who have no basic public services, labour protections or social entitlements, and who are exposed to the predatory activities of the "grileiros" – "land-grabbers" who invade and seize public property or private land belonging to others, using forged documents or, simply, intimidation and violence.

This practice of taking illegal possession of the land to sell it to large landowners or agribusiness interests, known as "grilagem", is carried out on a large scale in the Amazon rainforest, where the "grileiros" are the main culprits of deforestation.

In the Riozinho do Anfrísio reserve there are many interests at stake, ranging from land speculation to the sale of natural resources to money laundering.

In the reserve, which is rich in trees like the andiroba or crabwood tree, the copaiba or balsam tree, and mogno or mahogany, the main economic activity of the local residents today is harvesting the nuts from these trees, whose oils are in high demand by the cosmetics industry, as well as Brazil nuts and the berries from the açaí palm tree.

The families of Riozinho play an important role "fighting deforestation and environmental destruction," said Salazar, associate coordinator of the Xingú programme run by the Socioenvironmental Institute (ISA), an NGO that provides support to communities in the extractive reserves in the Terra do Meio region.

"Even though we're talking about a small number of people, these families protect and conserve biodiversity and the services provided by the environment. That's why they are very special, and also why they are an uncomfortable presence for many," he told IPS.

There are three extractive reserves in Terra do Meio: Riozinho; the 400,000-hectare Xingú River reserve, and the 300,000-hectare Iriri River reserve.

Salazar said the situation is especially complex in Riozinho, due to the construction of the Belo Monte hydropower dam on the Xingú River. The socioenvironmental costs of large infrastructure projects like dams are very high, he said.

"We warned that the dams would generate a real estate boom in the jungle, and would lead to major expansion of the local market, but the authorities did not consider the reserves vulnerable to the environmental impact of the enormous construction projects," he said.

"What do we want for the Amazon? That is the question we have to discuss. A broader public debate is needed," Salazar argued.

The environmentalist stressed the need to draw attention to the drastic situation faced by Belmiro dos Santos. "The protection granted by the authorities doesn't last long, and it's only a bandaid measure; the crucial question would be to discover who is responsible for the threats, and throw them into prison.

"Measures should be taken before something even worse happens. There are people losing their lives because they are fighting to defend the rainforest. And there are people who want to destroy everything," he added.

"The situation is very difficult," stated Belmiro dos Santos, who said he was afraid that if he were killed, his death would not do any good.