A farmer who had £70,000 worth of high-tech equipment stolen believes a gang spied on his premises with a drone.
A number of GPS units were stolen from tractors and combines belonging to Robert Redman, an agricultural contractor near Thame, Oxfordshire.
He said the thieves, who were caught by CCTV, knew the precise location of the machines and how to access them.
Thames Valley Police (TVP) said they had received numerous reports of similar GPS thefts since the start of May.
Computer equipment is used to guide and monitor machines during precision processes such as sowing and harvesting.
Mr Redman said: “I think it’s an organized group.
“Two weeks ago, a drone flew over and I believe it was them, who were monitoring these premises.
“They knew exactly where they were going.”
Equipment maker John Deere said its Starfire receivers and Greenstar cab displays come with PIN code protection, “meaning they can’t be used if stolen.”
A spokesperson said: “We can only urge owners of all high-value technology items to use the protection provided with, if necessary, the removal of components to further prevent the possibility of theft.”
Insurance company NFU Mutual said the cost of GPS theft nationwide between January and April this year was over £500,000 – and had doubled compared to the same period in 2022.
Police and TVP Crime Commissioner Matthew Barber said: “This is a really big deal. Since the war in Ukraine there has been a shortage of farm machinery in Eastern Europe and a lot of things that are stolen in the UK, we see it being tracked across Europe.
“There is a lot more to do. There is legislation pending in Parliament which will potentially require manufacturers to use forensic marking. This makes the sale much more difficult and easier for the police to follow. “