Tractors are the latest target in Britain for an international criminal gang making millions from stealing top-of-the-range models which are smuggled abroad.

The thefts are planned and carried out so meticulously that investigators believe they could be dealing with former Irish paramilitaries.

Hundreds of tractors are being stolen in an extraordinary crimewave that is worth £3 million a year and affects most counties in rural Britain. It is being investigated by police forces nationwide, working with the National Plant and Equipment Register in Operation Mermaid.

Stolen tractors, diggers, trailers and quad bikes are being transported openly and shipped overseas as far as Australia. The criminals have even managed on occasions to steal equipment that was seized and held by police.

They are particular about their pickings, and have a penchant for the distinctive green and yellow tractors of the John Deere brand. John Deere tractors usually cost between £63,700 and £75,000, and even second-hand models can be sold for up to £50,000. Some top-of-the-range tractors cost more than £100,000.

Another favourite is a machine known as a telescopic handler, similar in function to a forklift, which, if bought new, costs between £70,000 and £80,000. Quad bikes are also popular and vary in value from £2,000 to £5,000, while trailers are sold from £1,500 to £2,000.

Other manufacturers affected include New Holland, Case, Massey Ferguson, JCB, Caterpillar and Daewoo.Criminals have routinely been stealing two vehicles in a night from farms or dealerships. Then, within a few days, they break into a different dealership and steal identification documents and the black box, an electronic vehicle management system, from similar but unsold tractors.

Tim Purbrick, a manager at Equipment Register, said that the gangs removed the ID plates from the stolen tractors and replaced them with new plates obtained from the dealerships.

He said: “This effectively gives them a clean tractor which no-one has reported stolen or missing. They are therefore able to export the vehicles as far as Poland, other parts of Eastern Europe and Australia.

“These are sophisticated thefts by portfolio criminals. We think the gang has previously been involved in Irish terrorist operations, and that they have morphed the skills from terrorism to other serious criminal activity. They use counter-surveillance techniques, are forensically aware and have very good international criminal contacts. They have even stolen seized equipment back from the police, which shows how forward they are.”

Mr Purbrick said he was concerned that the failure to include plant theft in police targets issued by the Home Office may be fuelling the scam.

He said: “From the criminal perspective, there is a low-risk, high- reward balance in this activity. Drug smuggling is high risk, but the chances of being caught stealing a tractor are low, and stealing tractors is more lucrative.”

He said that in one case a John Deere 6920 tractor and a telescopic handler, worth a total of £115,000, were stolen from a farm in Melton Mowbray, Leicestershire. New ID numbers and black boxes from similar models were stolen from a dealership. The IDs were changed and the vehicles were transported to Humberside and then shipped to Rotterdam and Sydney. The proceeds were split between criminals in Britain and Australia who, Mr Purbrick suggested, would have made more than £50,000 each from the crime.

The costs of the operation are relatively low. Mr Purbrick suggested that thieves would steal a tractor and a new ID for about £1,000, and that shipping it overseas would cost about £500. He is urging all equipment owners and their manufacturers to tighten security.

Tractors are relatively easy to steal because most ignition keys are standard and can start any vehicle. Mr Purbrick is calling on the industry to start issuing unique keys for plant equipment.

“It’s crazy that a machine worth five times more than my car has less security. I have keys in my pocket that can steal any tractor in the country. My Swiss Army knife can do it,” he said.

A spokesman for John Deere said that the company was aware of the thefts, and that the industry may have to look again at security issues.

Enforcement action under Operation Mermaid is reaping rewards. In one incident, a John Deere tractor worth £42,000 was stolen from a farm in Weston-super-Mare, Somerset. A week later, a driver transporting the stolen vehicle on a low-loader stopped for a break at a service station on the M5, where the Equipment Register, with Gloucestershire Police, had set up a checkpoint.

Officers inspected the tractor and found that the serial number plates had been altered and that a false plate had been fixed to the vehicle. The tractor has since been returned to its owner and investigations into the criminal gang are continuing. Similar police checkpoints are now being established nationwide.

Pulling power

— Horse trailers: thefts estimated at £1.9 million

— New telescopic handlers are worth up to £80,000

— Quad bikes, worth as much as £5,000, are in high demand

— John Deere tractors are a frequent target

— The first engine-powered farm tractors were introduced in 1868. They used steam and were built as small road locomotives. Henry Ford produced an experimental petrol-powered tractor in 1907

— Tractors are the only motorised vehicles allowed on Sark, one of the Channel Islands

— Marina Lewycka’s father wrote a history of the tractor, which he failed to sell. Her debut novel, named A Short History of Tractors in Ukrainian, became a bestseller

— Tractors and machinery account for one third of all agricultural injuries. Tractor roll-over accidents are the most severe in agriculture

— A cross between a tractor and truck is known as a tructor, which can travel at speeds up to 25 mph

— Greece’s road and rail network was paralysed by tractor blockades in 1997, carried out by protesting farmers

Sources: www.machinery.uk.com , www.farmindustrynews.com, Times database

Times Recommends

• Everyone will get vaccine against swine flu
• Artificial sperm and the race to build a baby
• BBC staff lavished with trips to lobby for awards