By Joao Fellet
Fellow members of his indigenous group who had witnessed the incident quickly passed on the images to a wide network of supporters.
It took only hours for the case to make headlines abroad. And, in an unusually swift reaction, Brazilian Justice Minister Jose Eduardo Cardozo promised a thorough investigation.
Brazilian indigenous groups say they are increasingly using social media websites to spread their views and to counter what they say are the prejudiced views about them in local media.
For more on Amazon Indians, see Natural History Museum in Bob's Burgers and Tech-Savvy Surui Chief.
Below: "Indigenous Brazilian are using the latest technology to their advantage."