Customs officers have seized 26,000 litres of laundered fuel in Dublin.
Revenue's customs service at Dublin port stopped and carried out a routine inspection on a 40-foot truck as it was preparing to board a ferry to Britain.
The consignment of fuel was marked as 'dog food' and was contained in 26 plastic containers, each with a capacity of 1,000 litres, a statement said.
@The fuel and lorry were seized and a non-Irish national male is assisting Customs officers with their enquiries."
Revenue said the estimated value of the fuel is €30,000 with a loss to the Exchequer of €15,000. The value of the truck and trailer seized is approximately €35,000.
"As well as the risk to the Exchequer, this consignment also had serious health and safety implications as a variety of acids have been applied to the oil in the removal of the prescribed marker at the laundering stage," a Revenue spokesman said.