The images show several members of the Kawahiva tribe walking through dense foliage. Naked men carry bows and arrows, and a woman totes a child on her back. The woman runs away after noticing the camera, and one man briefly doubles back to investigate.
Loggers first reported the existence of the Kawahiva in 1999. A reservation was created last year in the western state of Mato Grosso, but members of the tribe still face grave threats from loggers and farmers.
The video was shot in 2011 by the government's agency overseeing indigenous matters, but was only released on Wednesday.