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 Irish Embassy in Seoul:Embassy of Ireland, Seoul
Leema Bldg. 13F., 142, Jongro 1-gil,
T: (02) 721 7200 / F: (02) 774 6458