The suspect – Ruben Dario da Silva Villar – is already being held on charges of using false Brazilian and Peruvian documents and leading an illegal fishing scheme. He denies being involved in the case.
A Colombian fish trader is set to be indicted as the mastermind of last year’s killing of British journalist Dom Phillips and indigenous expert Bruno Pereira.
Police have said Ruben Dario da Silva Villar provided the ammunition to target the pair, made phone calls to the confessed killer before and after the crime, and paid his lawyer.
Fisherman Amarildo da Costa de Oliveira, nicknamed Pelado, admitted that he shot Mr Phillips and Mr Pereira, and has been under arrest since soon after the killings in early June.
He and three other relatives are accused of being involved in the crime.
They all live in a poor community inside a federal agrarian reform settlement between the city of Atalaia do Norte and Javari Valley Indigenous Territory.
Mr Villar has denied any wrongdoing in the case.
Before Monday’s announcement, he was already being held on charges of using false Brazilian and Peruvian documents and leading an illegal fishing scheme.
According to the investigation, he financed local fishermen to fish inside Javari Valley Indigenous Territory.
In a statement, UNIVAJA, the local indigenous association that employed Mr Pereira, said it believed there were other significant plotters behind the killings who have not been arrested.
Mr Pereira and Mr Phillips were travelling in the remote area of the Amazon when they disappeared and their bodies were recovered after the confessions.
Mr Phillips was researching a book about how to save the world’s largest rainforest.
