SPOT checks at a Morpeth building site found two vehicles containing red diesel.
Police joined officers from HM Revenue and Customs to carry out the investigation, dip-testing several of the workers’ vehicles for traces of the fuel.
Two were found to contain red diesel and on-the-spot fines of £500 were issued to the owners. Had they not paid up, their vehicles would have been seized.
HMRC Senior Officer Julia Ryder said: “We are committed to working in partnership with Northumbria Police to help tackle this issue. The misuse of rebated fuels such as red diesel and kerosene is a criminal offence and if caught you could face a fine, have your vehicle seized and even face prosecution.”
Officers have the powers to carry out checks on vehicles they suspect to be carrying rebated fuel.
Meanwhile, Morpeth’s Neighbourhood Policing Team has warned people to be careful when storing or handling fuel.
Inspector Dave Simpson said: “I would like to remind people how dangerous it is to store fuel or drive around with canisters of fuel in your vehicle. The slightest trigger can cause fuel to ignite, which can have catastrophic consequences.”
For further advice contact police on 101 or e-mail firstname.lastname@example.org