Customs officers in Cork have seized 3.5 million cigarettes with a street value of €900,000 which were concealed in a shipment of furniture from Malaysia.
The cigarettes were uncovered at Cork Port late on Thursday night following customs investigations into bogus companies carrying out tobacco smuggling operations.
Mr Brendan Mulcahy of the Revenue Commissioners in Cork said the potential duty and tax loss to the Exchequer was in the region of €800,000.
No arrests have been made in connection with the seizure to date but the customs enforcement branch in Cork is liaising with customs agencies abroad with a view to establishing who was behind the operation.
Last July Customs officers in Cork seized five tonnes of contraband tobacco with an estimated street value of €1.25 million.
That shipment of cigarettes was concealed in earthenware containers which arrived from Bangkok in Thailand via Rotterdam in the Netherlands.
The tobacco had fake UK duty markings and was destined for sale in Britain rather than in the Republic.
In 2001, officers from Customs and Excise made 231 seizures of tobacco with a total weight of 4.7 tonnes.
Customs officials estimate that one in three packs of cigarettes sold in Britain and Ireland has been shipped illegally.