Brazilian search teams have found "apparently human" remains in the Amazonian rainforest river where a British journalist was last seen.
The "organic material" is being sent for forensic analysis, federal police said, along with blood found on a suspect's boat.
Journalist Dom Phillips and travel companion, indigenous expert Bruno Pereira, went missing after visiting fisherman Amarildo da Costa's riverside community of Sao Gabriel.
A Brazilian judge has ordered Mr Costa, charged with illegal possession of restricted ammunition, to be
held for 30 days while police investigate whether he may be involved in the disappearance.
Police have said Mr Costa, known locally as Pelado, was one of the last people to see Mr Phillips and Mr Pereira.
Detectives on the case told the Reuters news agency they are focusing on "poachers and illegal fisherman in the area" as they often clashed with Mr Pereira, who as a senior official with government indigenous agency Funai, had organised patrols of the local reservation.
Mr Costa's lawyers and family maintain he fished legally on the river and denied he had any role in the men's disappearance.
Witnesses say they last saw Mr Phillips, a freelance reporter who has written for The Guardian and The Washington Post, on Sunday.
The two men were on a reporting trip in the remote jungle area on the border between 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 Guardian said Mr Pereira had received a number of threats from loggers and miners in the region.
The pair's disappearance has attracted attention worldwide, in part due to Brazilian icons such as 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.