12,000 unstamped cigarettes were seized by Revenue officers during the search of a house in North County Dublin yesterday.
The cigarettes, branded Marlboro Gold, originated in the Ukraine and have an estimated retail value of over €6,400, representing a potential loss to the Exchequer of more than €5,600.
Following the search, which was under warrant, A Latvian man in his late 20s was questioned by Revenue officers.
Revenue says investigations are ongoing with a view to prosecution.
The operation was part of ongoing operations targeting the supply and sale of illegal alcohol and tobacco products in the shadow economy.