ATALAIA DON NORTE (Brazil) -- On Monday, the search for an Indigenous expert, a journalist, and a journalist missing in remote Brazil's Amazon continued after the discovery of a backpack and laptop submerged in a river.

Federal Police officers took the items by boat to Atalaia Do Norte, which is the nearest city to the search. Police said Sunday that they had identified the items as belonging the missing men. They also included a health card, clothes and a clothing of Bruno Pereira (the Brazilian Indigenous expert).

According to Atalaia Do Norte firefighters, the backpack was tied to a half-submerged tree. It's the end of the rainy season and a part of the forest has been flooded.

Pereira was an advisor to the Univaja Indigenous Association and its searchers were still looking for the men Monday, according Orlando Possuelo. A member of the group said that Federal police issued a statement disproving reports of bodies being found. However, police had previously reported that blood was found in the boat belonging to a fisherman, who is currently under arrest as the sole suspect in the disappearance.

Officers also discovered organic matter with an apparent human origin last week in the river. These materials are being analyzed.

Search teams had concentrated their efforts on a spot in Itaquai where the tarp of the boat used to hide the missing men was discovered Saturday by Matis Indigenous volunteers.

"We used a small canoe to get to the shallow water. Binin Beshu Matis from The Associated Press said that they found a tarp and shorts, as well as a spoon.

Phillips, 57 and Pereira, 41 respectively, were last seen near the Javari Valley Indigenous Territory's entrance, which borders Peru, Colombia. They had been returning by boat alone on the Itaquai from Atalaia Do Norte, but they never arrived.

There have been violent clashes between poachers, government agents, and fishermen in this area. The violence has increased as drug trafficking gangs fight for control over waterways to ship cocaine. However, the Itaquai isn't a well-known route for drug trafficking.

Police have stated that they are looking into possible connections to an international network that allows poor fishermen to illegally fish in Javari Valley Reserve, Brazil's second largest Indigenous territory.

The arapaima, the largest freshwater fish in the world with scales is one of the most important targets. It can reach 3 metres (10 feet) in length and weighs around 200 kg (440lbs). It is available for sale in nearby towns.

However, federal police are not ruling out other avenues of investigation such as drug trafficking.

Amarildo da Silva de Oliveira (also known as Pelado) is the only suspect in the disappearances. He is currently under arrest. Phillips and Pereira were accompanied by indigenous people who claim that he pointed a gun at them on the day they vanished.

According to his family, the suspect denied any wrongdoing and claimed that military police tortured him in an attempt to get a confession.

Pereira, who was previously the head of the Brazilian government’s Indigenous agency known as FUNAI, participated in numerous operations against illegal fishing. These operations usually result in the confiscation or destruction of fishing gear, and fishermen being fined and briefly held. Only Indigenous people can legally fish on their territory.

Maxciel Pereira dos Santos, a Funai official, was shot to death in Tabatinga in 2019, in front of his wife. The crime is still unsolved three years later. According to FUNAI colleagues, the slaying may have been linked to the victim's work against poachers and fishermen.

All riverbank communities were founded by rubber tappers. However, rubber tapping began to decline in the 1980s and people resorted instead to logging. This was also ended when the federal government established the Javari Valley Indigenous Territory (2001). Since then, fishing has been the main economic activity.

According to Manoel Felipe (local historian, teacher, and councilman), an illegal fishing trip in the vast Javari Valley takes around one month. A fisherman can make at least $3,000.

Felipe stated that the fishermen's financiers were Colombians. "Everyone was mad at Bruno in (the city) Leticia. This is no small game. They may have sent a gunman in to kill him."