Police are appealing for information after 71 sheep were stolen from a field in Hartington.
The incident occurred on Sunday night (March 10) when 71 Texel ewes in lamb were taken.
Police said: "The current trend in livestock thefts has suddenly taken an alarming upward curve with a large scale theft last night.
"A number of thefts – mostly sheep – have been reported lately, usually involving fewer than a dozen animals.
"These are bad enough and pose a real threat to the livelihoods of the farmers, but last night 71 Texel ewes in lamb were taken from a field at Hartington.
"This shows that we have a really serious problem in the area and we need your help.
"First of all, if anybody saw some nocturnal activity on Hyde Lane at Hartington then please get in touch. 71 sheep take some shifting so we’re hoping someone will have seen something.
"Secondly, please keep your eyes open and your mind set to inquisitive and don’t hesitate to ring the police if you see anything at all which gives rise to suspicion.
"Finally, we need information. Someone knows who’s doing this or may at least have an inkling. There’s no honour in protecting a thief and any information will be treated with complete confidentiality."
Anyone with any information is asked to contact police on 101.