Revenue officers seized cigarettes worth an estimated €1.4 million at Dublin Port on Wednesday.
The seizure was the result of routine profiling and was carried out with the assistance of a detector dog named Waffle.
More than 1.9 million cigarettes were seized.
The consignment of illegal cigarettes, which were branded “Manchester”, had an estimated retail value of €1.4 million, representing a potential loss to the Exchequer of about €1.1 million.
Revenue said the seizure was part of its 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,” it added.