South Island police are searching for offenders who stole and slaughtered cattle from a Banks Peninsula property and left the animals' hides hanging on a fence.
Detective senior sergeant Neville Jenkins said the cattle were taken sometime between January 20 and January 26, when the incident was reported.
The hides were left hanging on a fence on the property.
Jenkins believed those responsible had knowledge of the rural section and knew what they were doing.
A property adjacent to where the incident occurred was also missing five Friesian bulls.
The loss was discovered around the same period, Jenkins said, though there was no evidence of the second lot of cattle being slaughtered.
Jenkins was urging farmers and rural residents to report any unusual activity following the incident.
"For example, something suspicious could be a vehicle that's been left on the side of the road, one you hear at odd times during the night, or maybe people walking around who look out of place," he said.
"Security options for farmers to consider include installing CCTV or wireless alert systems which can activate an alarm in your house to alert you that someone is in your shed."
Jenkins said it was important cattle had NAIT tags - a national identification tag - which recorded any stock movement. The cattle stolen were all tagged.
This was critical to the biosecurity of the dairy industry, particularly with the current mycoplasma bovis situation, he said.