Authorities in the Amazon investigating the disappearance of a British journalist and an Indigenous advocate have yet to find any evidence of a crime three days after the men went missing in a remote corner of the rainforest. Police in the far west of Brazil said on Wednesday their inquiries into the disappearance of Dom Phillips, a longtime Guardian contributor, and Bruno Araújo Pereira, an advocate for Indigenous people, had led to the arrest of one man. The suspect was caught in possession of drugs, a shotgun and ammunition restricted for military use, but was not named. Earlier in the day police sources said they had detained a man named Amarildo da Costa de Oliveira on similar charges. However, the Amazonas state police chief told reporters it was too early to link any suspect directly to the pair’s disappearance. “We have material that makes us suspect there is a link to the fact,” said Carlos Alberto Mansur. “But it’s still just a suspicion. It’s still being investigated. “For now, our main job is searching, and our hope is still to find them alive. That they had a problem with their boat, that they went up a river, that they are lost in the jungle. It’s the jungle, it’s a very complex area. “We still don’t have a strong indication a crime was committed.” Da Costa goes by the nickname Pelado and was reported to have threatened Phillips and Pereira and a group of 13 Indigenous people on Saturday morning. A witness to the encounter told the Guardian that Da Costa and two other armed men threatened the group while they were stopped at the side of the Itaquaí river in Amazonas state. Da Costa’s boat was later seized by police. Pereira, 41, a longtime advocate of the Indigenous tribes in a vast and remote jungle area, had received death threats for his work helping protect Indigenous groups from drug traffickers and illegal miners, loggers and hunters who covet land in a region rich with natural resources. He and Phillips were last seen on Sunday morning while traveling by boat through the Javari region of Amazonas state. They were returning from a two-day reporting trip but did not arrive as scheduled at the town of Atalaia do Norte. Phillips, 57, was in the region researching a book on sustainable development there. He received a fellowship from the Alicia Patterson Foundation to write the book, and was aiming to finish it by the end of this year. His wife Alessandra Sampaio made an emotional appeal for authorities to speed up their search on Tuesday and as the case hit the headlines in Brazil, personalities from the sporting and arts worlds joined in. Three-time World Cup winner Pelé posted his support, as did Everton and Brazil forward Richarlison and Walter Casagrande, a former Brazilian player who is now a well-known sports broadcaster. Singer Gaby Amarantos, actor Camila Pitanga and Sonia Guajajara, an Indigenous leader who was recently chosen one of Time magazine’s most influential people of 2022, all made appeals on social media, as did Corinthians football club. Further afield, the US climate envoy, John Kerry, said he would look into the case. In Britain, the shadow foreign secretary, David Lammy, urged Brazilian authorities “to do all they can to find them as soon as possible and for the Foreign Office to use all the diplomatic channels at its disposal”. There is considerable anger over the lack of urgency shown by Brazilian authorities, and particularly the far-right president, Jair Bolsonaro. The search has been beset by delays and contradictory statements by Brazilian military officials in charge of the region. In the first 24 hours after their disappearance was reported, the army said it was awaiting orders before mobilising. The navy then said it was dispatching a helicopter and two boats, before the army finally said it had employed jungle specialists in its search. Bolsonaro showed little sympathy in his first comments on Monday, calling their trip “an adventure that was not recommended”. “Anything could happen,” he said. “It could be an accident, it could be they’ve been executed. We ask God that they are found soon. The armed forces are working hard in the region.” Security chiefs claimed the search operation had expanded by Wednesday with 250 people, two planes, three drones and 16 vessels now involved. Jungle warfare specialists were being deployed to try and find traces of the men in the Javari’s dense forests, said General Plácido from the Amazon region army command.