Revenue officers have seized 30kgs of 'Amber Leaf' tobacco in Shannon and Limerick.
The unstamped tobacco had a retail value of over €15,400, representing a loss to the Exchequer of €12,900.
On Monday, 12kgs of tobacco were seized following routine operations.
Yesterday, officers seized 18kgs of tobacco following a search of a shop and an adjoining house in Limerick City.
A woman in her 30s was interviewed at the scene.
The seized tobacco was found in packages which had arrived from the Netherlands and were destined for addresses in Limerick.
Investigations are ongoing.