A total of 460,000 cigarettes were seized by Revenue at Dublin Port.
Some 300,000 cigarettes branded "Minsk", with an estimated retail value of €210,000, were discovered by officers today.
They represented a potential loss to the Exchequer of approximately €167,000.
A total of 160,000 cigarettes branded "NZ Gold", with an estimated retail value of more than €113,000, were seized by authorities.
They represented a potential loss to the Exchequer of approximately €89,000.
In both instances, the illegal cigarettes were discovered concealed in containers that had arrived into Dublin Port from Rotterdam.
These operations were carried out as a result of routine profiling with the assistance of Revenue’s mobile x-ray scanner.
A Revenue spokeswoman said: "Investigations are ongoing.
"These seizures are part of Revenue’s ongoing operations targeting the shadow economy and the supply and sale of illegal tobacco products.
"If businesses or members of the public have any information regarding smuggling, they can contact Revenue in confidence on free phone number 1800 295 295."
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