The seizure was part of a routine search of a premises by Revenue officers in Westmeath.
Over €350,000 worth of drugs have been seized in the midlands.
During a search of a premises in Athlone, Revenue officers discovered 17.9kg of cannabis herb in two parcels, with a value of €359,000.
The parcels originated in Spain and Italy, and were destined for addresses in Dublin and Louth.
Investigations are ongoing.