Over 18,000 cigarettes seized by Revenue officers yesterday were initally detected in Portlaoise and AthloneMail Centres.
The smuggled cigarettes originated in Bulgaria and Ukraine.
In the first of two follow-up operations, Revenue Officers acting under court warrant and assisted by detector dog Harvey searched a house in Newcastle West, Co. Limerick.
They interviewed a Lithuanian man and seized 8,880 cigarettes branded NZ Gold.
In the second operation, Revenue officers also acting under court warrant, searched a house in Dublin, where they interviewed a Bulgarian man and seized 10,000 cigarettes, branded Marlboro and Karelia.
Investigations are continuing in both cases, with a view to prosecution.
The cigarettes,with a total retail value of over €9,400 represented a potential loss to the exchequer of over €7,800.