In a joint operation by Gardaí, Revenue and the Health Products Regulatory Authority a total 60,000 vials were found following a number of searches in the county this morning (Thursday).
Other medicines, including human growth hormone and products for erectile dysfunction, were also found as was evidence of an illegal medicines manufacturing operation.
In addition, a car was seized for breach of VRT regulations, along with a substantial amount of cash.
The operation involved gardaí from Buncrana and Letterkenny, revenue enforcement officers from Letterkenny, Dundalk and Monaghan, and enforcement officers from the HPRA.
It was also supported by the Revenue’s detector dog.
One person has been arrested and a cross border investigation is continuing.