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 all reports of lost or stolen passports.

You should return the passport to the Embassy of Ireland at:

The Embassy of Ireland,

Ireland House,

541 Orchard Road,

Liat Towers, 8th Floor,

Singapore 238881.