Christine Scott has nothing but contempt for sheep rustlers. "Those that are doing it and those that are receiving it are the lowest of the low," she says. Only this year, Scott, who has been farming in the gritstone fells of the Trough of Bowland in Lancashire for the past three and a half decades – alone with her daughter since the death of her husband in 2009 – lost 70 Swaledale ewes with lambs at foot.
"We counted them at clipping time and they were all there but in August they had gone off the fell," she says. "Whoever is doing it has extremely good dogs. That is the most hurtful part. The fact of the matter is that it is one of your own kind."
In previous years, Scott and her husband would spend all night up on the lonely moorland tops, splitting the hours between dusk and dawn into two long, cold shifts sitting hunched in a Land Rover while the other slept back at the farm house with their children.
Although they witnessed plenty of furtive movements in the darkness, no one was ever brought to justice. "The police had their suspects and we had ours but, unless you actually catch someone, there is nothing you can do," she says.
While it may appear an atavistic, almost picaresque crime to outsiders, sheep rustling has a toxic effect on trust among rural communities. It is also imposing crippling financial cost on small farms struggling to make a living, and posing a potential threat to human health by undermining disease control regimes and possibly flouting animal welfare standards. For while crime is generally reported to be falling across Britain in both the city and the countryside, sheep rustling, one of the most ancient of all offences, is on the rise.
Between 2010 and 2011, insurance claims by farmers for stolen livestock rose 170 per cent, according to NFU Mutual, which provides cover for three quarters of UK farmers. In 2012, numbers rose again and it is estimated that 69,000 animals were stolen last year at a cost to farmers of about £6m.
This month, as sheep are brought down off freezing hillsides to overwinter in more clement pastures, reports are once again starting to come in of missing livestock from Scotland to the South-west.
Unlike other common theft items, particularly electronic goods whose criminal resale price has collapsed in recent years, illegal meat sold into the legitimate food chain now commands nearly £8 a kilo compared with £6.77 in 2009. Fattened lambs can fetch between £200 and £300 at market.
Tim Price of NFU Mutual says that higher meat prices combined with better security for farm machinery meant that thieves had turned their attention to livestock, with hundreds of sheep being stolen in single raids.
"It's deeply worrying because rustling can have a devastating effect on farmers' businesses and lives. It's not just about the financial impact – it involves a huge amount of extra work for farmers to replace lost sheep, and the knowledge that thieves are targeting livestock can seriously affect farmers' health," he says.
Cumbria is one of the worst-affected areas of the country. Here on the border, local families can still trace their lineage back to the revivers who for centuries eked out a precarious survival in the lawless buffer zone between the warring armies of England and Scotland, plundering neighbours' livestock and pretty much anything else they could lay their hands on. The reality of their criminal exploits was never quite as romantic as imagined by Sir Walter Scott and others – so, too, the modern-day rustlers.
Today, the M6 provides a fast route out of the county for organised gangs. With lorries, quad bikes and well-trained sheep dogs, they can rapidly transport their quarry to slaughter or to be fattened well away from the scene of the crime.
Detective Sergeant Andy Lamb, of Cumbria Police, says thefts of sheep had cost farmers there £368,000 during the past three years although the true figure is likely to be higher. This year, the force launched Operation Ambient in a bid to improve intelligence and raise awareness. Last month, it held a sheep identity parade in Kirkby Stephen for 150 stolen ewes that were seized during arrests made across the north Pennines.
But police forces are only just beginning to build a country-wide picture of sheep rustling. Under the terms of the 1968 Theft Act, stolen animals are logged simply as missing property, meaning that there are no accurate figures on the actual number of crimes. Since the launch of a new crackdown, in which officers visit local markets and stop and search livestock wagons to check movement papers, intelligence is growing, says Det Sgt Lamb.
"We are seeing an increase in the reporting of thefts to police and people are becoming more confident about contacting us so we are starting to see a truer picture," he says.
For years, wild stories have circulated of organised foreign gangs rounding up sheep from fields, butchering them and selling the meat to city curry houses. The evidence – such as it exists – reveals a more prosaic, if equally unsettling, picture.
"To get a lot of sheep off the fells takes a degree of skill," says Det Sgt Lamb. "When you look at the options, these sheep are going to enter the human chain most likely at auction where farmers are selling them as their own."
For the police, operating with modest manpower over wide areas where there is no CCTV and many victims are often reluctant to come forward, either from embarrassment or an unwillingness to be seen to blame their fellow farmers, detection is difficult. Even specifying a time when an offence has taken place can be problematic, with sheep often left on remote fells for weeks, if not months, unattended. But there have been successes.
Last year, Lancashire Police secured the first conviction for sheep rustling in a quarter of a century. Farmer John Kirkham, 66, admitted stealing 55 pregnant ewes worth £15,000 from a field in the Ribble Valley owned by another farmer against whom he had a grudge. He was sentenced to nine months imprisonment, suspended for a year, while shepherd James Hesketh, 22, admitted handling stolen goods and was ordered to serve a 12-month community order. The sheep were found 100 miles away in County Durham. Passing sentence at Preston Crown Court, judge Mr Recorder Roderick Carus QC said the convictions dispelled the suggestion that such rural crime was carried out by "city folk". "In this case," he said, "the culprits were part of that very community and it is no surprise to hear that both of you have suffered with rejections by members of that same community – you wouldn't expect anything else."
Earlier this month, local man Robert Birnie, 47, was convicted of stealing more than 200 sheep and trying to sell them at markets across north Cumbria. He was eventually discovered after police traced the true owner through the animals' ear tags. Birnie will be sentenced in January.
Sanctions against sheep rustlers have in the past been considerably less lenient. The coveting of a neighbour's ox or donkey has been proscribed since Biblical times. And while the death penalty for sheep, horse and cattle stealing was only repealed in Britain in 1832, transportation to New South Wales continued – sometimes for the theft of a single ewe – for decades afterwards.
Modern-day farming methods have added a new dimension to the human dangers associated with sheep rustling. Graham Winder, of Cumbria Trading Standards, says animals are routinely administered veterinary medicines. "Normally, all medicines given to livestock will have a withdrawal period when the residues within the meat will deplete over time. People who are stealing sheep do not know when or what an animal is being treated with. The law is there for a reason," he says.
An animal being treated for sheep scab, for example, will take three months from the end of treatment before it can be declared fit for human consumption.
Police have uncovered illegal slaughterhouses. One on a farm near Harrogate, North Yorkshire, discovered in 2005 was being used to butcher sheep for the halal restaurant trade. Stephen Rossides, the director of the British Meat Processors Association, says many of those living in rural communities had rudimentary knowledge of slaughtering and butchery, although illegal abattoirs pose serious dangers.
"If [slaughtering] was being done outside of an approved premises, it would almost certainly breach animal welfare requirements. It is important that, at the time of killing, animals are treated humanely, and there is a real risk that welfare is compromised," he says.
Legitimate slaughtermen will stun a sheep with an electric shock before using a knife to quickly sever the main blood vessels, resulting in a quick and painless death. When the kill is unregulated, there may be no such safeguards. And there are other risks, too. "At this time of year, animals are wet and dirty and it is important that there is no contamination from mud or faeces," says Mr Rossides.
The use of electronic tags and even retinal scanning looks set to make sheep theft more difficult in the future. In the meantime, farmers are being urged to keep hedges and fences in good repair and, most importantly, to report any suspicious behaviour. Not all are expected to go to the lengths of a farmer near Oakhampton in Devon who dyed his flock orange to ward off rustlers.
Like many working in the rural economy, Harry Hutchinson, a commoner with rights to graze on 2,000 acres of land between the Lake District and the Yorkshire Dales National Parks, believes more could be done. He has just retrieved 100 sheep from Baugh Fell, a large and remote 6,000-acre expanse where he shares grazing rights with a dozen other farmers.
This year, he has been lucky. All his flock are present and correct, although he has not been so fortuitous previously. Last year, 15 sheep disappeared. It is just possible they died of natural causes in the frigid spring but unlikely. "Who we suspect of doing it, I have no idea. Everyone appears honest. We have to stay put and keep on and trust each other. There is no one who you think is particularly shady but there's nothing concrete that we could say is suspicious," he says.
"This is the problem – you don't know who is doing it. But they would need good sheep dogs, know the lie of the land to have spied it out."
Meanwhile, sheep rustling continues to divide communities. "Nobody likes grassing on their neighbours," he says. "But if we are prepared to talk about it openly then we are more likely to catch up on it."