GAS meter thieves are being warned that they are putting themselves and others in danger by tampering with the systems.
The warning follows a spate of thefts of meters from houses in south east Northumberland.
Numerous empty houses in Ashington, Bedlington and Blyth have been targeted.
Police believe the offenders are using the stolen meters to replace their own in order to defraud gas suppliers.
Superintendent Mick Paterson, of the police’s Northumberland area command, said: “I’d urge home-owners to be vigilant and report anything suspicious.
“It’s obviously dangerous for people to tamper with gas, and these thieves are putting people in danger with their actions.”
“A fraudulently replaced gas meter is extremely easy for engineers to spot.
“We’ve set up procedures so when engineers carry out checks and find gas meters which they think have been tampered with or stolen, they will report them to us and we’ll come and pay the homeowner a visit.”
Anyone with information about gas meter thefts is asked to call police on 101 ext 69191.