THE mystery beast which has slaughtered scores of lambs in the past few weeks and left a farmer fearing for his livelihood has struck again.

Police are investigating the spate of attacks, which all occurred at night on a County Durham farm.

Last night, however, they played down suggestions that the attacks could be the work of a big cat, such as the fabled Durham puma.

Farmer Dick Wade, who has lost 26 animals in less than two weeks, vowed he would show the culprit no mercy, no matter what it turned out to be.

Mr Wade spoke out after waking up yesterday morning to find a further seven lambs savaged in his fields at Primrose Side Farm, at New Brancepeth, near Durham City.

The most likely suspect, according to police, remains a large dog - probably one from a nearby village.

In all the instances the lambs have been newly-born and have been killed by a crushing bite to the head. Some have been partly eaten.

Mr Wade said: "I am at my wits' end. I don't get any compensation for this either. If I ever find the culprit, I will shoot it."

He said: "The sheep are in five fields, so it is impossible to keep an eye on them all during the night.

"With the foot-and-mouth disease restrictions, we are unable to move the sheep out of the field."

His wife, Pauline, said last night: "This is really getting my husband and son down. Every morning now, I see them coming in from the fields looking so dejected."

Durham wildlife liaison officer Sergeant Eddie Bell, who is investigating, said: "Looking at the pattern of the attacks, and the fact that they have all happened over a short period of time in a small area, it could be a dog living not far away, possibly from one of the local villages.

"It could be a dog with a powerful jaw, such as a German shepherd or collie dog. Somebody must have an idea that their dog is getting out at night."