SHEEP rustling on the North York Moors "probably carried out by one of our own" is angering hill farmers.

Three incidents were reported to police last week.

An Aislaby farmer was shattered to discover his complete flock had disappeared from a field overnight. More than 350 in-lamb gimmers were stolen in a theft which has mystified both him and NFU representatives.

Greg Proll, of the Stokesley and Cleveland branch of the NFU, said: "In-lamb gimmers are not usually sold to kill, so we are not sure what has happened here.

"It looks as though the flock was stolen in one fell swoop. A huge tri-axle lorry could have managed to carry all the sheep. It would have blocked the road, but we have no reports of anything being seen.

"It is difficult to follow up such a case, as one sheep looks like another when it has been killed and hangs on a hook."

Two other incidents were reported, although in much smaller numbers, at Helmsley and Danby.

Former Danby farmer, Coun Herbert Tindall, vice-chairman of the North York Moors National Park Authority and chairman of Danby Parish Council said: "The incidents of sheep rustling are really upsetting this small community. We had problems of this kind a few years ago. I believe the upsurge in sheep prices may well be the cause. It is a despicable act; farmers need to be extra vigilant."

Tony Flintoft, who farms on moorland above Osmotherley, was very angry and upset at the latest thefts. He founded Sheepwatch, a surveillance group, following the last spate of rustling a few years ago.

He said: "I have had quite a few sheep stolen myself. We are saying someone with expert knowledge of handling and moving sheep must be responsible. You cannot move so many sheep so quickly unless you have expert knowledge. Sadly, it looks as if those responsible are our own - a farmer or farmers."

Sheep farmers had suffered enough over the past few years, he said, and, after the foot-and-mouth crisis and then restocking and movement problems, farmers were only just getting back on their feet.

He believed this type of animal could have been stolen to make up numbers for Defra trading officers' visits if farmers had lost sheep in other ways. "Farmers are heavily penalised by the Ministry if the numbers do not tally. There is a lot of money at stake here," he added.

Other sheep could end up anywhere, being killed and on butchers' hooks.

When Sheepwatch was operating fully the last time, rustling figures dropped significantly, he said. "I am operations manager for the surveillance team, which can be called out at a moment's notice, with police backing, if suspicious circumstances are reported.

"Last time I was out four nights per week on operations and still had to carry out a day's work too. It nearly ruined my life."

A Defra spokesman said: "Clearly rustling is a criminal offence, as is removing tags and marks from stock. Rules are in force regarding the movement of animals and we deplore any rustling activity."