Customs officers have seized 2,800 litres of contaminated fuel, red diesel and kerosene from a filling station in Caerphilly.
Road fuel testing officers arriving at the site last Wednesday and found two large fuel tanks containing what claimed to be duty-paid white diesel selling at £1.25 a litre.
Checks showed the fuel contained large quantities of kerosene, which attracts a lower rate of duty. The kerosene had been added to white diesel in a process known as ‘stretching’.
Officers later seized and removed 990 litres of the contaminated fuel, 990 litres of red diesel and 820 litres of kerosene.
HM Revenue and Customs says as enquiries continued, a number of individuals arrived at the filling station to buy diesel.
Officers seized ten commercial and private vehicles which tested positive for red diesel or contaminated fuel. These were restored after payment of a penalty plus the duty on a full tank of white diesel.
Stuart Fenton from HMRC’s Road Fuel Testing Unit said, "White diesel selling at 15p less than the normal price might seem like a fantastic deal, but in this case it was no bargain. Kerosene makes white diesel more combustible, and prolonged use would undoubtedly damage the engine of any vehicle."
Investigations are continuing.