Dom Phillips: Blood found on suspect's boat in Amazon

Traces of blood have been found on the boat of a suspect arrested in connection with the disappearance of a British journalist and a Brazilian indigenous expert in the Amazon, authorities said Thursday, as calls grew to intensify the search.

Dom Phillips, 57, a regular contributor to The Guardian newspaper, and Bruno Pereira, 41, a specialist in indigenous peoples, were reported missing on Sunday after they ventured into the middle of the Amazon rainforest.

"Traces of blood were found on the boat of Amarildo da Costa de Oliveira, 41," Brazil police said in a statement, adding that the suspect known as "Pelado" was arrested on Tuesday.

"The material collected is on its way to Manaus," the capital of the Amazonas state, for expert analysis, the statement added.

It was accompanied by images of investigators taking photos of what appeared to be a small bloodstain on a blue tarp inside a motorboat with peeling paint.

The statement is a grim twist in the ongoing search for the two men, whose fate remains unknown.

The Brazilian authorities said they are hopeful of finding the pair alive but do not exclude any outcome, including that of homicide, in a region where trafficking is rife.

High-profile personalities and environmental and human rights groups have rallied to the cause, urging President Jair Bolsonaro to step up the search.

"Where is Dom Phillips? Where is Bruno Pereira?" asked the journalist's sister, Sian Phillips, in a statement to the media during a gathering of around 30 people in front of Brazil's embassy in London.

"We want the UK authorities to put pressure on the Brazilian government," she added, before she and other family members were received by the ambassador.

"We want to carry on with the search. We want to find out what is happening to them and we want anyone responsible for any criminal act to be brought to justice. We want a persistent deep and open investigation," she added.

She blamed the Brazilian authorities for delaying the search but said they "all have hope" that the pair will be found.

"He is a great writer and journalist. He is a caring man. He cares about the environment. He loves Brazil," Phillips said of her brother.

"He's a great guy and we love him with all our heart."

Paul Sherwood, Phillips' brother-in-law, said the family had "been assured that everything has been done that can be done."