Police in Southland are investigating the death of 500 sheep at a farm near Gore. They appear to have suffocated.
Police say the sheep were discovered dead in a gully on a farm at Mt Wendon, about 45 kilometres north of Gore.
They say it isn't clear whether the deaths are suspicious, as the sheep may have smothered themselves after being spooked by an unwelcome presence on the property, such as poachers.
The stock loss is estimated to be worth thousands of dollars.
Police say poaching is becoming an increasingly common problem in the area and they're keen to hear from any farmers who have seen suspicious activity, especially around Mt Wendon, in early February.
Federated Farmers says those who deal with large numbers of sheep will know smotherings are not uncommon.
Southland provincial president, Russell MacPherson says it's possible the sheep smothered naturally and were not provoked.