A bowser belonging to a private company, transporting 6,600 litres of Lanka Auto Diesel, has been seized while its driver, assistant, and two brokers have been arrested by the Meegoda Police.
The four were arrested following a tip-off that the diesel was being sold at a higher price.
The suspects, between the ages of 22 and 47, are residents of Homagama, Waga, Kandy, and Urubokka.
The bowser was purchased under the name of a private company, while the bowser was found to have changed its route and was attempting to provide the diesel to another private company in Meegoda.
The group had claimed that they require Rs.830 per litre and later increased prices to Rs.900 per litre.
Police are inquiring into the racket at present.
Police said with the sale of a litre at Rs.900 the suspects were able to incur a profit of Rs.6 million.