Owners and drivers of Ford Transit vans are being warned to be vigilant after thieves in South Yorkshire bypassed locking systems.
The county's force said a number of thefts from vehicles had been reported where the thieves had managed to gain entry without forcing the locks.
On each occasion no damage was done and it is believed the offenders are using a device to bypass the lock system.
Crime reduction officer Dene Tinker said: “We are aware of this method and are working hard to investigate these offences and find those responsible.
“It’s vital that Transit owners and drivers are vigilant. We know it may take time at the end of a long day’s work to remove valuables but we do recommend you do so, especially overnight.
“I also appreciate it isn’t always an option for those who have nowhere else to keep them. If this is the case, please consider investing in a robust van vault where you can lock away all your valuable tools."
“I would also advise that all van owners fit additional security such as Loading Door Keepers to prevent door peeling. Fit an alarm and boost security by installing additional Slamlocks or deadlocks independently of the manufacturers. This will increase security of any items inside the van and they also offer a visual deterrent on the outside of the van."
He went on to advise anyone storing work tools in a van to consider insuring those items separately.
"This is important because most standard van insurance policies do not cover loss of tools left in a van overnight," Mr Tinker said. "In fact, some policies state that you can’t store tools in your van unless it meets certain security requirements. Don’t get caught out, and check.
“I am aware that many self-employed tradespeople are dependent on their van and work tools. Damage to the van and time to restock an extensive collection of specialist tools can take time. The disruption is frustrating and costly, as without the necessary tools, it’s not possible to complete the jobs currently being worked on or take on new projects.”
Anyone with information about the thefts is asked to call South Yorkshire Police on 101.