The rare camera footage shows him chopping down a tree from a distance through foliage.
He's believed to be aged between 55 and 60 but no one knows his name or where exactly he came from.
It's believed he's lived on his own in Brazil's Amazon for 22 years.
He is an indigenous man, believed to be the last surviving member of his tribe, whose remarkable solitary existence defies all modern expectation of life in 2018.
The man has been monitored by Brazil's Indian Foundation since 1996, when the last of his people are believed to have been wiped out in an attack by farmers and loggers.
The latest footage was shot in 2011, but released this week by the Indian Foundation, who head into the forest in Rondonia state to check for traces he is alive on a near monthly basis and leave him tools to help him farm.
They have seen he has planted corn, potatoes, papayas and bananas within the wilderness.
An attempt was made to make contact with him more than a decade ago but he rejected it.
The team that tracks the man found fresh footprints and a newly cut tree as recently as May.
"We don't know who he belongs to," said Altair Algayer, the coordinator of the team.
"This man, who is unknown to us, even after losing everything, including his people and a series of cultural practices, proved that, even like that, alone in the forest, it is possible to survive and resist joining mainstream society," Algayer added.
"I believe he is much better off than if, way back, he had made contact."