Fuel was stolen from four cars in Wirksworth last week.
Some time between Saturday, August 27 and Wednesday, August 31, a thief cut the fuel pipe from a Ford Focus, Vauxhall Corsa and a Chevrolet Matiz. Fuel was also siphoned from a Mitsubishi Canter.
All the vehicles were parked at a car park in Old Lane at the time of the thefts.
Anyone with information should call police on 0345 123 3333 or Crimestoppers on 0800 555 111.