Concerns about British journalist Dom Phillips, who disappeared in Brazil, and his Brazilian companion, Bruno Pereira, are growing: while searching for the two missing persons in the Amazon rainforest on Friday, investigators examined possible human remains and a place where something was apparently buried, as reported by the fire brigade and police. On Thursday, investigators had already found traces of blood in the boat of an arrested suspect.

The 57-year-old Phillips, who writes regularly for the British newspaper The Guardian as a freelance correspondent, had been researching a book about violence against indigenous people together with Pereira in the Javari Valley near the border with Peru. They have been missing since Sunday. Gold miners, poachers and drug gangs are active in the region. According to indigenous organizations, the men had previously been threatened.

Firefighter Geonivan Maciel told journalists on Friday that investigators are now following a new lead in the case: they are investigating a suspicious site of “dug up earth” in the village of Cachoeira on the banks of the Itaquai River, where the men were last seen were.

“It looks like someone was digging or burying something at the site,” Maciel said. So far there is no clear evidence, “but we will see if there is anything that we can use to find out something about the two missing men.”

The Brazilian federal police later announced that the investigators had found “apparently human organic material” during the search. It was initially unclear whether it was found in the place described by Maciel. According to the police, investigators took samples from Phillips and Pereira’s apartments for a DNA comparison.

On Wednesday, investigators arrested 41-year-old Amarildo da Costa de Oliveira. According to the police, drugs and cartridges for an assault rifle were found on him during a random check. Witnesses said they saw the man chasing Phillips and Pereira’s boat. Traces of blood were later found in the man’s boat and are now being examined in a forensic laboratory in Manaus, the capital of the state of Amazonas.

Pereira, who works for the government agency for indigenous affairs (Funai), regularly receives threats from illegal loggers and miners trying to trespass on the lands of isolated indigenous groups. In recent years, violence has increased in the region due to the presence of illegal miners, hunters and fishermen.