Revenue Officers have seized more than 9.5 million contraband cigarettes in the past week.
The seizures were made in Dublin, Meath and Tipperary as part of of intelligence-led operations.
On Thursday, 7,800 cigarettes branded 'MG', 'Marlboro Gold' and 'Royal Classic' - and 3.5kgs of 'Flandria' tobacco - were seized when three houses in inner-city Dublin were searched.
The search took place under warrant in an on-going operation targeting illegal trade in Moore Street.
While on Wednesday afternoon, Revenue officers searched a house in Cashel, Co Tipperary.
There they seized over 39,000 'MG' brand cigarettes.
A man in his 40s was questioned and a file is currently being prepared for the Director of Public Prosecutions (DPP).
Also on Wednesday, 6.6 million cigarettes were seized from a warehouse in Co Meath.
The container of 'Royale Pacific' brand cigarettes originated in Vietnam, and had arrived into Dublin Port on Monday from Rotterdam.
The smuggled cigarettes were described as 'Shower room linen baskets' on the manifest.
And last Thursday, 2.9 million cigarettes were seized at Dublin Port - the 'Jim' brand cigarettes had also originated in Vietnam.
Revenue say investigations are ongoing in all cases.
The combined value of the seized product is €5m, representing a total loss to the exchequer of almost €4m.
