Brazil's federal police are continuing to search for the missing boat of UK journalist Dom Phillips and Indigenous expert Bruno Pereira as investigators prepare to begin testing human remains found buried in the Amazon.
It comes as DNA testing of blood found in the boat of the man charged with their murders has indicated it is not that of the British journalist.
Investigators say tests to determine if it was Pereira's have proved inconclusive.
Police also told the PA news agency on Friday that despite "exhaustive searches" officers had failed to find the missing men's boat.
Fisherman Amarildo da Costa de Oliveira, 41, confessed to shooting the men and led officers to human remains he had buried in an area of the Amazon near where the pair disappeared.
In their latest announcement about the case, police reiterated the remains had yet to be identified. They said testing would begin on Friday and results were expected next week.
A federal police plane flew the remains into Brasilia on Thursday evening.
The discovery of the human remains came after a 10-day search for the missing British journalist and his Brazilian companion, who disappeared on June 5.
Brazilians authorities have so far arrested two men in relation to the pair's suspected murders. On Thursday, police said da Costa de Oliveira - the prime suspect - confessed to using a firearm to kill Phillips and Pereira.
More arrests are expected.
Police gave no immediate explanation of a motive for the killing, but officials earlier suggested that Pereira's work to stop illegal fishing in an indigenous reserve had angered local fishermen.
The family of Phillips reacted to the news of da Costa de Oliveira's confession to his murder with heartbreak.
"We ... extend our deepest sympathies to Alessandra, Beatriz and the other Brazilian family members of both men," Phillips' brother-in-law Paul Sherwood said.
Friends and colleagues of the long-time campaigner for the Amazon and its Indigenous people also paid tribute to the journalist.
Jonathan Watts, The Guardian's global environment editor, said his long-time friend had died in "an undeclared global war against nature and the people who defend it".
In an opinion piece, Watts also took aim at Brazilian authorities and President Jair Bolsonaro.
"The police refused to put a helicopter in the air after the two men were reported missing, and the military said it had the capacity to search but wasted more than a day while waiting for orders," he wrote.
Watts said the president, who earlier accused Phillips and Pereira of taking an "adventure" that was "ill-advised", had "encouraged illegal logging and mining, dismissed indigenous land rights, attacked conservation groups, and slashed the budgets and personnel of forest and indigenous protection agencies".
He said what happened to the men was "part of a global trend".
"Over the past two decades, thousands of environment and land defenders have been killed worldwide. Brazil has been the most murderous country during that time," Watts said.