By Adrian Cowell
Producer/director, The Jungle Beat
Illegal logging in the Amazon is a huge business. The high stakes bring considerable danger and the constant threat of assassination for those trying to protect the environment.
Illegal logging has devastated large areas of Brazil's Amazon rainforest
Twenty years ago, as we filmed Chico Mendes lead the fight to halt the devastation of the rainforest, we watched his aides taking precautions against the many threats on his life.
Despite their efforts, Chico was gunned down in December 1988.
Today there is a new arch-enemy for the illegal loggers in the Amazonian State of Rondonia. He is Walmir de Jesus, the regional head of Ibama, the enforcement agency of Brazil's Ministry of the Environment.
As we began filming him last year, the threats of assassination were equally frequent.
"You can be sure that all the businessmen and ranchers who have received enormous fines from Walmir de Jesus," one of his opponents warned us, "have a desire for his elimination."
Why is assassination so constant a threat for anyone defending the Amazon forest?
Walmir's mission is to fight deforestation and, in particular, logging inside the reserves
The answer lies in the enormous interests involved.
It is estimated that the Amazonian timber trade is worth close to $1bn (£574m), and that much of the trade is illegal.
More than half the forest in Walmir's state of Rondonia has already been cut down, and so most of the remaining, more valuable, timber is in the reserves which Walmir protects.
They are under incessant pressure from the mafia of Amazonia and anyone who tries to prevent their looting is at considerable risk.
Unlike most criminal organisations, the Amazonian mafia has wide popular support.
When Walmir sent a team to inspect the sawmills in the town of Sao Domingos do Guapore - they were reported to be buying timber stolen from the reserves - his team was surrounded by 400 shopkeepers and townspeople.
They were prevented from entering the timber yards.
Rondonia is largely deforested so the only large sources of timber are inside the reserves
And when Walmir returned with an army convoy to enforce the inspection, he was challenged by the state's political establishment.
The reason is that much of Amazonia was opened up by illegal land-grabbers and loggers moving into the forest far ahead of the government.
It was they who paved the way for local businesses and industries to establish themselves in the area and it is they who now dominate much of the regional politics.
This is particularly true of the remoter areas where the outreach of the federal government has often been too weak to apply the law.
Last year, the Brazilian government announced a campaign to reduce deforestation by enforcing the country's environmental laws.
This was bound to produce a bitter and head-on confrontation with many of these local communities. The fines Walmir issued in towns like Sao Domingos bankrupted sawmills and put many people out of work.
Permits and movement orders are often forged to avoid restrictions and fines
During 2005, a new satellite system was introduced, enabling Walmir's helicopter to reach areas of deforestation while the cutting of the trees was still in progress.
Two of the fines we saw him issue were for between £200,000 and £300,000, more than enough to bankrupt most ranchers.
And it is the ranchers who are the moneyed elite in most Amazonian communities.
Finally, an operation mounted by the federal police arrested over 100 people - many in Walmir's government department, Ibama - for corruption linked to forged documents for illegal timber sales.
Partly as a result of all this, the rate of deforestation in 2005 decreased by 40%.
In reply, the loggers' protests blocked highways all over Amazonia, paralysing transport, holding up thousands of trucks for many days on end and cutting off food from the state capitals.
Political parties put pressure on the government and today, many vested interests in the Amazon regard Ibama - and its representatives like Walmir - as a direct threat to their economic survival.
The battle for the world's largest tropical forest is heating up.
And in a country which has one of the world's highest murder rates, it should be no surprise that environmental protection often leads to assassination.
Earlier this year, Dorothy Stang, an American nun, tried to defend an environmental project in the eastern Amazon.
As her paid assassins walked towards her, she pulled out her bible and read a few words... before their bullets left yet another martyr to the environment lifeless in the Amazon forest.
The Jungle Beat was broadcast on Thursday, 17 November, 2005 at 2100 GMT on BBC Two.