Livestock rustlers have stolen fifty white-faced Texel Cross sheep from farmland in North Yorkshire, police say.
North Yorkshire Police are appealing for more information regarding the theft, which happened between 20 to 26 October.
The incident happened on a field on moors between Darnbrook and Arncliffe.
Each sheep has an identification tag in their ear with the flock number of UK123738 and red mark on the shoulder.
"Any info please call 101 ref number NYP-26102020-0093. We are reminding farmers to be vigilant of suspicious activity on their land," the force said.
Figures show that livestock worth £3 million were stolen from UK farms last year.
Large-scale sheep thefts over the past two years have contributed to a 19.4% rise in value since 2017, according to rural insurer NFU Mutual.
This makes rustling the most costly crime for the UK’s farming sector after agricultural vehicle and machinery theft.
How do I prevent livestock rustling?
Preventing rustling is not as easy as putting a padlock on a building or fitting a security system to a tractor.
However, there are a number of steps farmers can take to reduce the risk and technology is now providing effective ways of tracing stolen livestock.
To deter livestock thieves, NFU Mutual advises farmers to:
• Ensure stock is clearly marked and records are up to date
• When possible graze livestock in fields away from roads
• Check stock regularly - and vary times of feeding/check ups
• Consider a high-tech marking system such as TecTracer which puts thousands of coded microdot markers into a sheep’s fleece
• Join a Farm or Rural Watch scheme to share information about rural crime in your area
• Ask neighbours to report any suspicious sightings to the police, or to give information 100% anonymously to the Rural Crime Hotline 0800 783 0137
• Dial 999 immediately if an incident is taking place - do not approach criminals