Lincolnshire Police are warning scrap metal merchants and site managers to keep an eye on copper stores after a steep rise in thefts in the county. Since mid-May, police have received 10 reports of copper and scrap metal thefts from building sites, cabling companies and farms.
Copper has recently increased in value so demand for the metal is high.
Scrap merchants have been warned to be wary of individuals trading in large stocks of copper or metal.
But Lincolnshire Police said the price of copper had now started to fall and thieves were increasing the risks they took for a small return.
The latest thefts saw two bundles of copper taken from the roof rack of a car parked in North Hykeham on Wednesday and two copper canisters taken from business premises in the town on Thursday afternoon.