Customs officials seized thousands of litres of illegal diesel during a major raid in Dungiven yesterday.

The operation was carried out at a unit to the rear of Glenshane Enterprise Centre, off Ballyquin Road, around midday.

More than 5,500 litres of illegal fuel, which customs officials believe was contaminated, were seized during the operation.

Forecourt pumps were also removed from the site.

It is not known how long the “huckster” operation had been in place at the site.

Several diesel containers and pumping equipment were also found at the site where it is understood both and red diesel were being sold.

A spokeswoman for Revenue and Customs described the operation as a success.

“Large chains can buy fuel in bulk but the small independent trader can’t compete with this.

“We believe the fuel seized is contaminated and people are putting that in their car.

“Generally it is laundered using acid which causes engine corrosion. This operation has done the public a big favour.“

The spokeswoman also revealed that the Revenue and Customs Criminal Investigation’s Branch have launched a probe to establish who was behind the illegal selling operation.