Revenue officers, assisted by gardaí, have seized cannabis with an estimated value of more than €16 million at Rosslare Europort.
Approximately 783kg of herbal cannabis and 70kg of cannabis resin was discovered in an unaccompanied freight unit.
Revenue said that the unit was stopped and searched after its arrival on a ferry from Bilbao in Spain.
The drugs will be analysed by Forensic Science Ireland.
The operation was a result of risk profiling with the assistance of detector dog Jasper and an x-ray scanner, Revenue said.
No arrests have been made, according to gardaí.
They said that investigations are ongoing.
The seizure is part of Revenue's ongoing operations targeting organised crime groups and the importation of illegal drugs.
