Car owners are being warned to be on their guard after a string of sneak fuel thefts in Hemel Hempstead.
Within the past month there have been five cases of petrol tanks being damaged and the fuel being collected in a container and stolen.
All of the offences took place in the Chaulden area of the town between September 23 and Monday of this week.
Cars parked in Long Chaulden, Paddock Way, Wellbury Terrace, Leggfield Terrace and Rowcroft have all been targeted.
Det Insp Justine Jenkins, investigating, said: “We don’t often see crimes like this. Someone is targeting vehicles in the Chaulden area for fuel and it is causing considerable damage to the vehicles, which is extremely costly to repair.
“If you see someone underneath a vehicle or tampering with it, please contact police immediately so we can respond. We’d rather you call and it turns out to be a legitimate act, than not at all.”
Call police on the non-emergency number 101 with information.