High fuel prices have triggered a wave of thefts of low-tax red diesel, used for tractors and other agricultural machinery, from farms across Britain.

NFU Mutual, the leading provider of insurance to rural enterprises, reports that the number of claims for stolen red diesel are up 30 per cent in the first five months of the year. So far, there have been 50 claims involving a total of £100,000.

However, the loss of diesel alone is not the only problem for farmers. Often thieves leave the pump nozzle open, so that diesel runs away on to the ground leading to serious pollution. The cost of the clean-up is more than the price of the fuel.

The cost of red diesel is 65p a litre, of which 9.69p is tax. A year ago the average price of red diesel was 38p a litre. In 2002 farmers paid 17p a litre.

A red dye is added to farm diesel sold by registered agricultural merchants and distributors so that officers from HM Revenue & Customs (HMRC) can identify if farmers are abusing the rules and using farm vehicles running on cheap fuel on main roads.

Tim Price, a spokesman for NFU Mutual, said that average claims for diesel theft were £15,000 to £30,000, although the bulk was to pay for cleaning up spillages on the farms, including water courses.

Eddie Cowpe, an arable and dairy farmer who runs 350 acres in Salmesbury, Lancashire, is one of the victims. Thieves stole red diesel from his 10,000-litre tank, but after taking what they could allowed 8,000 to 9,000 litres to spill on to his land.

He is insured for the damage, but believes the cost of the clean-up could be as much as £70,000. “They broke the padlock to the yard, took what they wanted and let the rest go to waste. It is very annoying. We have had to dig out the yard, intercept field drains and get a company to mop up the local brook. We think it will cost us £70,000 to clean up.” He has put a secure fence around the tank in an attempt to deter thieves.

Mr Price said: “Farmers have improved security on their tanks but we have seen an increase in thefts, perhaps not surprisingly in view of the oil-price increases. In the first five months of this year we have seen a 30 per cent increase in farm diesel thefts.” He said that there were reports of enforcement officers stepping up patrols to check vehicle tanks for misuse of red diesel on the roads and others of thieves trying to filter the red dye from diesel to sell it as full-tax diesel.

HMRC confirmed that patrols were continuing routine checks for illicit fuel use, but said that there are no figures for red diesel crime. Anyone caught misusing red diesel could expect a £500 fine for a first offence and for the vehicle involved to be seized until the fine is paid. Persistent offenders or larger-scale misuse of red diesel can attract a prison sentence of up to six years if the case is held in a magistrates' court and seven years in a Crown court.

Mr Price said that farm premises in remote locations were relatively easy pickings for determined criminals. Thieves were quick to seize the opportunity to steal valuable commodities and red diesel was the latest example.

“Last year we had a scrap metal rush - copper, lead and aluminium irrigation pipes, which were disappearing from farms because the scrap price had risen,” Mr Price said. “The same thing is happening with oil. Thieves cotton on to the value of a commodity and target it.”

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