Revenue officers seized nine million cigarettes at Dublin Port this morning.
The smuggled cigarettes were found in a refrigerated shipping container and were disguised as frozen food, which came from a vessel travelling from Rotterdam in The Netherlands.
The 'illicit white' cigarettes were branded FEST and have an estimated value of €4.4m.
This would mean a loss of €3.77m to the taxpayer.
The seizure took place as part of an intelligence led investigation and a probe is ongoing by Revenue Officers.
"This seizure is part of Revenue’s ongoing operations targeting the shadow economy and the supply and sale of illegal tobacco products," said a spokesperson.
"If businesses or members of the public have any information regarding the smuggling they can contact Revenue in confidence on free phone number 1800 295 295."