This information was just released and if it all checks out we might have a major breakthrough, will keep you posted as the story develops.
This is a Google Translation from Portuguese.
Brazilian UFO Magazine - www.ufo.com.br.
The Documents Released - www.ufo.com.br/documentos.
An English Version of the Letter - http://www.ufo.com.br/public/carta_foz/iguassu_falls_letter.pdf.
My thanks to Raf at Project Avalon to posting this information.