Up to €150,000 worth of cannabis has been seized at Portlaoise Mail Centre today.
Revenue officers seized 7.5kg of herbal cannabis with the help of a sniffer dog.
The drugs were found hidden in parcels from Nigeria, addressed to a location in Dublin.
The investigation is on-going.
Revenue have asked anyone with information to contact their Confidential Freephone line on 1800 295 295.