Eight million cigarettes smuggled into the country from China have been seized by customs officers and gardai.
The haul, worth €3.4m, was discovered in a container attached to a truck on the M1 near Drogheda, Co Louth, last night.
Two men were arrested in relation to the find, with a 56-year-old later released without charge. A file is being prepared for the Director of Public Prosecutions.
The second man, aged 41, remains in custody in Navan Garda Station.
The unstamped contraband Benson & Hedges cigarettes had arrived at Dublin Port in the 40ft container from China.
The Revenue's Customs Service said that if sold, the haul would have cost the exchequer nearly €3m.
Last year 178.3 million cigarettes worth €75.1m were seized.
Retailers Against Smuggling, the representative group for Ireland's tobacco retailers, commended the work of officials but said higher fines need to be imposed on cigarette smugglers.
Spokesman Benny Gilsenan said 2011 has begun where 2010 left off, with Ireland continuing to be a target for national and international smugglers.
"Major criminals are using Ireland for the illegal cigarette trade due the high profit margins they can make from selling illegal tobacco and the paltry fines that are being handed out by the judiciary," he said.
"The average fine for a person caught smuggling in 2010 was just over €500 despite the maximum fine being increased to €126,970 in last year's Finance Bill."
Mr Gilsenan said that, despite 31% of the adult population smoking - approximately one million people - shop sales are continuing to fall with the Irish Exchequer losing more than half a billion in 2010.
"The fines are meaningless and pathetic and there is now a real onus on the judiciary to finally step up and hand out sentences that befit the crime," he added.
"It's no exaggeration to say that livelihoods are on the line because of tobacco smuggling. These people need to be hit with the maximum fine permitted by law in all cases."
Customs have urged anyone with information on the smuggling or ale of illegal cigarettes to call the confidential free phone number 1800 295 295.