Six months after predicting his own murder, a leading rainforest defender has reportedly been gunned down in the Brazilian Amazon. José Cláudio Ribeiro da Silva and his wife, Maria do Espírito Santo, are said to have been killed in an ambush near their home in Nova Ipixuna, in Pará state, about 37 miles from Marabá.

According to a local newspaper, Diário do Pará, the couple had not had police protection despite getting frequent death threats because of their battle against illegal loggers and ranchers.

On Tuesday there were conflicting reports from about whether the killing happened on Monday night or Tuesday morning. A police spokesperson said there were reports of a "double homicide" at the settlement called Maçaranduba 2.

In a speech at a TEDx event in Manaus, in November, Da Silva spoke of his fears that loggers would try to silence him. "I could be here today talking to you and in one month you will get the news that I disappeared. I will protect the forest at all costs. That is why I could get a bullet in my head at any moment … because I denounce the loggers and charcoal producers, and that is why they think I cannot exist. [People] ask me, 'are you afraid?' Yes, I'm a human being, of course I am afraid. But my fear does not silence me. As long as I have the strength to walk I will denounce all of those who damage the forest."

Roberto Smeraldi, founder and director of the environmental group Amigos da Terra, who worked with Da Silva in the Amazon, said he had been in a meeting with Brazil's president, Dilma Rousseff, discussing changes to the forest code when the news broke of Da Silva being killed. "He was convinced he would be killed one day," Smeraldi said. He added that Da Silva had been "very active" in the fight against illegal forest burning and logging. According to Brazilian media reports, Rousseff has asked her chief of staff, Gilberto Carvalho, to offer support to the murder investigation.

"We now have another Chico Mendes," said Felipe Milanez, an environmental journalist from São Paulo, referring to the Amazonian rubber-tapper who became an environmental martyr after his murder in 1988. Milanez said that in a recent phone conversation with Da Silva's wife she had suggested the situation was "getting very ugly". Milanez added: "He knew the threats were very real. He was scared."

A 2008 report compiled by Brazilian human rights groups listed Da Silva as one of dozens of Amazon human rights and environmental activists "considered at risk" of assassination.