Brazilian police said on Friday that they had arrested a man known as "Colombia" as authorities investigate his possible involvement in the killings of British journalist Dom Phillips and indigenous expert Bruno Pereira in the Amazon rainforest.
The two men disappeared in early June in a remote area of jungle on the border with Colombia and Peru. A fisherman later confessed to their murders and led police to the bodies following major search efforts.
The fisherman, Amarildo da Costa Oliveira, had previously clashed with Pereira over his efforts to combat illegal fishing in protected indigenous territory.
"Colombia" is involved in the regional fish trade and federal police told reporters on Friday they are still attempting to confirm his real name.
A detective in the case previously told Reuters that Costa, the main suspect, worked for Colombia.
Reuters could not immediately contact Colombia for comment.
Colombia voluntarily appeared at the police station in the Brazilian border town of Tabatinga, telling police he had no involvement in the killings or illegal fishing, said Eduardo Fontes, the federal police superintendent in Amazonas state.
He was arrested for presenting false identification, after showing police Colombian and Brazilian IDs with different names, Fontes said.
"We are deepening the investigations to see if there are more people involved or not in this criminal event, to see if the crime was ordered and for us to discover the real motivation," the police superintendent said.
Pereira had previously served at federal indigenous affairs agency Funai but was sidelined under right-wing President Jair Bolsonaro, who has sought to weaken the body. Pereira left Funai to help indigenous mount their own patrols against poaching and other invasions of their land.
Phillips, a freelance reporter who had written for the Guardian and the Washington Post, was doing research for a book on the trip with Pereira.
(Reporting by Jake Spring; Editing by David Gregorio)