The driver of a car stopped in Mullinavat on Wednesday subsequently tested positive for cocaine.
Gardaí from the Thomastown roads policing unit were on patrol in the South Kilkenny area when they noticed a vehicle driving erratically.
The driver was arrested after the results of an oral fluid test proved positive for cocaine.
They were taken to Thomastown Garda Station and the results of a blood sample taken are now awaited.