Revenue officers have seized over 4,400 litres of laundered diesel at a filling station in Cavan.
Two oil tankers and 3,900 litres of untaxed kerosene were also seized at the premises.
The Revenue made the discovery on Tuesday, but have yet to disclose the exact location.
The seizure is part of Revenue’s ongoing operations targeting the supply and sale of laundered diesel.
A more effective fiscal marker was implemented in Ireland and the UK from the beginning of April this year, which is being used in marked fuels and was ultimately was assisted the detection of these laundered fuels.
If businesses or members of the public have any information regarding the smuggling or sale of illegal diesel, they can contact Revenue in confidence on free phone number 1800 295 295.