These are a tribe of Indans that live in a remote region of Brazil. They have been lost for about 100 years and yesterday (18th of August 2000) someone found them. I am pretty sure though that if you asked them,
interviewer How does it feel to have been lost for 100 years
they would reply,
Naua Indian What do you mean lost? we've been right here?

As I am reading the article it gets stranger. They were offically identified as authentic by a government anthropologist
Naua Indian Of course we're authentic you bloody idiot
Who went on to say that they had lost their cultural heritage because they had been working with white men as rubber tappers.

The spokesman says "However, they look like you and I and they have forgotten many of their traditional ways."

So the reason people thought they were lost is because they didn't look like traditional indians any more.