What do I do if I find a passport I'd reported lost/stolen?
Never travel on your passport if it has been reported lost or stolen. You run the risk of being stopped at border crossings, as Interpol keeps a record of lost or stolen passports.
If living in Brazil, you should return the passport to:
Passport Officer
Embassy of Ireland
SHIS QL 12 conjunto 05 casa 09
Lago Sul
Brasília - DF
CEP 71630-255
Brazil