Tesco has taken out advertisements in the national press today in an attempt to reassure customers over the horse meat scandal.
The supermarket said it is reviewing its approach to its supply chain and building a traceability system including DNA testing.
The Department of Agriculture''s investigation into the contaminations are now focused on a cold store in Naas.
Agriculture Minister Simon Coveney said QK Cold Stores has informed the department that frozen beef trimmings imported from Poland, were tested by them and some showed positive for horse DNA.
European Union governments have ordered an EU-wide programme of DNA tests on beef products, to assess the scale of the horse meat scandal.