Surge in illegal gold mining destroys vast areas of the Amazon
9 August 2014 Last updated at 00:04 BST
A surge in illegal gold mining has destroyed vast areas of the Amazon forest in Brazil.
Authorities say five thousand miners are operating in an indigenous reserve the size of Belgium, polluting rivers and the ground with toxic substances.
BBC Brasil's Joao Fellet has joined environmental agents in an operation in the Kayapo indigenous land.