Searches by up to 100 gardaí and Department of Agriculture officials has led to the seizure of a significant amount of illegal animal drugs.
What is described as a "significant quantity of illegal remedies were discovered" in Co Waterford and Co Monaghan. A diesel laundering plant was also discovered in Waterford which officials from the Revenue Commissioners are now investigating.
In a statement, gardai said officers from the National Bureau of Criminal Investigation assisted by gardai from counties Monaghan, Cavan, Waterford and Carlow were involved in the search.
In a simultaneous operation Police Service of Northern Ireland officers carried out a similar search in Tyrone and Fermanagh.
No arrests have been made.
