An uncontacted tribe has made first contact with the outside world in the Amazon, home to more groups that have not had contact with the outside world than any other area in the world.
According to FUNAI, Brazil's indigenous authority and the organisation that filmed the natives shortly after their initial contact, there are 77 uncontacted tribes in the Amazon.
The native men in the video come from uncontacted tribes living along the border between Peru and Brazil. It is estimated that around 600 natives have settled there, belonging to four separate groups.
But the group also seasonally moves for turtle eggs, which could be another reason why they came into contact with the Ashaninka native people of northern Brazil along the banks of the Envira River, near the Peruvian border.
The men belong to a tribe from the Panoan linguistic group, a group of languages spoken by indigenous people in the area of the Amazon. There is no knowledge of what the groups call themselves, however.
Very little is known about indigenous people such as this, known as Uncontacted Indians. However, they are most likely descendants of tribe members who were able to escape the enslaving or wiping out of indigenous groups at the end of the 19th century, during the rubber boom.
Isolated Amazonian Indians on the banks of the Envira River, Brazil (Getty)
Members of these tribes live in communal houses, and live off what they hunt and collect, including forest birds, animals, fish, fruits and nuts.
What is known about such groups is that they want to remain uncontacted. They have previously shot arrows at airplanes and tend to hide out deep in the Amazon in order to remain protected.
However, their desire to stay uncontacted has become increasingly difficult, due to illegal activity encroaching on their territory. This is also putting such tribes at serious risk, as outsiders bring common bacteria into the natives' lands, exposing them to potentially life-threatening harm.
Though we have largely developed immunity to common diseases like measles or the common cold, uncontacted Indians have not, meaning they are especially vulnerable to them.
Members of these tribes live off what they hunt and collect (Getty)
FUNAI recently treated seven members of Uncontacted Indian tribes for the flu, reportedly after non-Indians invaded their land with guns. Although once they returned to their communities they were free of the virus, they may be carrying other sorts of bacteria which could bring harm to their tribe once they return.
Survival has responded to the issue by beginning a campaign to protect the groups from such illnesses spread by members of the outside world.
In March 2014, Peru and Brazil signed an agreement to monitor the protection of such tribes' land.