Cocaine with a street value of five million euro has been seized after an international investigation.
The haul was recovered by Customs officials and Garda officers in Fermoy, Co Cork, after arriving at Cork Port on a ship from Rotterdam in the Netherlands.
A 56-year-old German man and a 45-year-old Irish man were arrested at the scene at industrial premises in Bartlemy, Fermoy.
During follow-up searches another two Irish men, aged 42 and 65, were arrested in Dublin and a 46-year-old Hungarian man was arrested in Cork.
All five men are being questioned under the Drug Trafficking Act at Cobh, Crumlin, Terenure and Midleton Garda stations.
"The goods have now been removed to a secure location where an in-depth search of the consignment will be undertaken," said a Customs spokesman.
The operation involved Customs, the Garda National Drugs Unit, Europol, Interpol and Dutch law enforcement agencies.
Customs said it received strategic intelligence from abroad on an international drug smuggling gang.
"Investigations are continuing," said a Garda spokesman.