Brazilian Soldiers take part in a search operation for British journalist Dom Phillips and indigenous expert Bruno Pereira, who went missing while reporting in a remote and lawless part of the Amazon rainforest near the border with Peru, in Atalaia do Nor
Brazilian Soldiers take part in a search operation for British journalist Dom Phillips and indigenous expert Bruno Pereira, who went missing while reporting in a remote and lawless part of the Amazon rainforest near the border with Peru, in Atalaia do Norte, Amazonas state, Brazil, June 10, 2022. Reuters / BRUNO KELLY

Brazilian investigators are skeptical that remains found in a river could be from a British journalist who went missing in the Amazon rainforest on Sunday, two police officers involved in the case told Reuters.

On Friday, federal police had announced finding "organic material" that was "apparently human," raising expectations of a breakthrough in the search for reporter Dom Phillips and his travel companion, indigenous expert Bruno Pereira.

However, a federal police officer and a state detective, both of whom requested anonymity to discuss the case, said the material's location and condition raised doubts about whether it could be connected to the missing men.

A federal police spokesperson did not immediately respond to requests for comment.

The remains were found near the port of Atalaia do Norte, a town more than 40 miles (65 km) downstream from where Phillips and Pereira were last seen on a slow-moving river, the sources said. The material's condition suggested it could have been scraps from a nearby butcher rather than remains carried far downstream, they added.

One of the sources said it seemed likely the material was from an animal and not human, but that it had been sent for forensic analysis out of an abundance of caution. The other said the origin would only be clear after that analysis.

Witnesses said they last saw Phillips, a freelance reporter who has written for the Guardian and the Washington Post, last Sunday. His companion Pereira, an expert on local tribes, had been a senior official with government indigenous agency Funai.

The two men were on a reporting trip in the remote jungle area near the border with Peru and Colombia that is home to the world's largest number of uncontacted indigenous people. The wild and lawless region has lured cocaine-smuggling gangs, along with illegal loggers, miners and hunters.

The pair's disappearance has echoed globally, with Brazilian icons from soccer great Pele to singer Caetano Veloso joining politicians, environmentalists and human rights activists in urging President Jair Bolsonaro to step up the search for them.

State police detectives involved in the investigation have told Reuters they are focusing on poachers and illegal fisherman in the area, who clashed often with Pereira as he organized indigenous patrols of the local reservation.

Police have arrested one fisherman, Amarildo da Costa, known locally as "Pelado," on a weapons charge and are keeping him in custody as they investigate whether he is involved in the men's disappearance

Costa's lawyers and family have said he fished legally on the river and denied he had any role in the men's disappearance.

Some 150 soldiers had been deployed via riverboats to hunt for the missing men and interview locals, joining indigenous search teams who have been looking for the pair since Sunday.