About 1,500 litres of red diesel was stolen from a farm at Fulstow.
The theft occurred between 1am and 5am on August 31. A police spokesperson said: “A large vehicle would have been needed to remove this quantity and weight of fuel. The offenders may have used up to 60 small drums or used a vehicle equipped with large tanks to remove the fuel from the scene.”
On the same day a suspicious green Peugeot car was seen around farm machinery at Brackenborough near Louth at 1.20am and police say this may be linked to the Fulstow theft.
Anyone with information should call police on 101.