In connection with the death in Amazon of a British journalist, a third suspect was arrested.
Dom Phillips and Bruno Pereira, an indigenous expert, were both reported missing two weeks ago. Human remains have since been recovered.
Forensic tests confirmed the death of Mr Phillips, while other remains found are believed to be those of Mr Pereira.
Jefferson da Silva Lima, a man named Jefferson, has become a local cop station.
Two brothers are being held for their alleged involvement with the murders.
Officers earlier this week said that the main suspect, Amarildo Da Costa de Oliveira, was the one who led them to the burial ground.
Officers also learned that he used a gun to commit the crime.
According to police, Phillips was shot in his chest while Pereira was shot in his head and abdomen.
An autopsy revealed that the victim was using a “firearm with standard hunting ammunition”.
They were last seen at the Javari Valley Indigenous Territory bordering Colombia and Peru on their boat, on the Itaquai river.
This area has witnessed violent conflict between poachers, fishermen, and government agents.
Alessandra Sampaio, Mrs Phillips’ spouse, stated that his family can now say “goodbye with love” in a statement.
She said, “We also start our search for justice. I hope the investigations will exhaust all options and provide definitive answers to all pertinent details as quickly as possible.