There's actually quite a few, as of yet, uncontacted tribes in the South American rain forests. Brazil has a no contact policy with tribes who haven't already made contact, and rigorously patrols the surrounding wilderness from the air to make sure no one tries to contact them.
From June 21st of this year.
The Brazilian government confirmed this week the existence of an uncontacted tribe in a southwestern area of the Amazon rain forest.
Three large clearings in the area had been identified by satellite, but the population's existence was only verified after airplane expeditions in April gathered more data, the National Indian Foundation said in a news release Monday.
The government agency, known by its Portuguese acronym Funai, uses airplanes to avoid disrupting isolated groups. Brazil has a policy of not contacting such tribes but working to prevent the invasion of their land to preserve their autonomy. Funai estimates 68 isolated populations live in the Amazon.
The most recently identified tribe, estimated at around 200 individuals, live in four large, straw-roofed buildings and grow corn, bananas, peanuts and other crops. According to Funai, preliminary observation indicates the population likely belongs to the pano language group, which extends from the Brazilian Amazon into the Peruvian and Bolivian jungle.
The community is near the border with Peru in the massive Vale do Javari reservation, which is nearly the size of Portugal and is home to at least 14 uncontacted tribes.