Raiders hit five farms across Norfolk stealing more than a dozen GPS systems worth hundreds of thousands of pounds in less than a week.
Hi-tech satellite guidance systems, which can cost up to £15,000 each and are a popular target for organised criminal gangs, were stolen from tractors and farm machinery.
Police are investigating whether the thefts in Wroxham, Great Ellingham, Marsham, Salhouse and Frettenham are linked.
Norfolk police’s rural crime officer PC Chris Shelley urged farmers and landowners to be vigilant.
“We received one report of a GPS theft in October and now 13 GPS systems have been stolen in the space of seven days, so clearly this was a targeted effort to steal high-value agricultural equipment,” he said.
“With nights drawing in, there are more opportunities for criminals to strike during hours of darkness so please take every step to secure your equipment.”
In Great Ellingham, thieves damaged the lock of a tractor between November 24 and 25, and stole a GPS monitor, while in Marsham a GPS dome receiver and screens were stolen from two tractors between November 23 and 28.
GPS domes, screens and an iPad were stolen overnight from four tractors and crop sprayers at Wroxham on November 28 while high-value equipment was also taken in Salhouse on November 28 and Frettenham sometime between November 26 and 30.
The kit is used by farmers to help with precision crop management.
Jon Chandler, a long-serving former Norfolk police officer who is now a director of rural security firm Farmwatch, said previous cases had involved international gangs entering the UK with lists of farms to target.
He said: “It’s common for gangs to target an area over a few nights and then move on to another county. It is highly organised as a criminal activity.
“Most of the kit ends up going outside the UK, stolen pretty much to order and then ends up on various online selling sites.”
Some Norfolk farms have been hit by multiple losses of the £10,000 systems in thefts which can cause costly disruption.
North Norfolk farmer Kit Papworth said: "It's a huge issue - it's been a huge issue for ages because no one will do anything about it.
"It would be easy for manufacturers to create security features which disable these extremely expensive items but they have failed to do so and so farmers are regularly targeted by highly sophisticated thieves, stealing many hundreds of thousands of pounds worth of equipment in a single night.
"All that farmers can do is remove the equipment from their machines and lock it away. This raises insurance premiums for the whole industry."
Police action on rural crime and thefts of agricultural equipment has been made a top priority by Norfolk police and crime commissioner Giles Orpen-Smellie.
PC Shelley said police worked closely with the farming community to share intelligence and advice to protect equipment including reviewing security measures and marking devices and recording serial numbers.
Any witnesses or anyone who saw suspicious activity in these areas can call PC Shelley on 101 quoting the relevant investigation number. Alternatively, they can contact Crimestoppers anonymously on 0800 555 111.
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