Il Nuovo Postiglione - Fourth arrest in Amazon murders of journalist, guide: police

The man presented himself to police to deny claims in the press that he may have ordered the murders, police chief Eduardo Fontes of the Amazonas state told reporters.

He was arrested for allegedly presenting fake identity documents.

Fontes said the man, known as "Colombia," told police that he buys merchandise from fishermen in the area where the murders happened.

He said that one of his suppliers was Amarildo da Costa de Oliveira, known as "Pelado," who is under arrest after confessing to his role in the crime.

Phillips, 57, and Pereira, 41, were shot dead while returning from an expedition in a remote region of the rainforest that is plagued by drug trafficking, illegal gold mining and fishing.

Phillips, the author of dozens of articles on the Amazon and a long-time contributor to The Guardian newspaper and other major news organizations, was traveling to the Javari Valley as part of research for an upcoming book.

Pereira was serving as his guide, and had previously traveled with him to the area.

An outspoken defender of Indigenous rights, Pereira had received multiple death threats prior to his death.

Police are investigating a possible link to illegal fishing on protected Indigenous lands as a motive for the murder.

"We are investigating whether that person known as 'Colombia' ... participates in any illegal fishing scheme, whether he finances" that activity, said Fontes, adding the man had denied any involvement.

"We don't know what his true identity is," Fontes added.

The man had documents from Brazil, Colombia and Peru, each in a different name, he said.

Three men are under arrest for the murders and five others stand accused of helping to dispose of the bodies, which were found 10 days after the pair disappeared.

S.Maiolo--INP