The gruesome discovery of sheep's heads on a Milton farm has led to calls for farmers to be vigilant against rustlers.
The heads of two ewes were discovered by a Milton farmer on his property last week and a steer was shot on a farm near Clinton, police say.
The incidents mean farmers need to be aware of those visiting their property or their neighbours' properties and anything suspicious should be reported to police, Federated Farmers Otago president Stephen Korteweg says.
''It's a really serious offence and the worst thing, for the farmer affected is [thinking] will there be any more,'' Mr Korteweg said.
''Neighbours have to band together and be as vigilant as possible.''
The Milton farmer, who did not wish to be identified, said his dogs discovered the severed heads of the ewes on Thursday morning.
''I would have been none the wiser if the dogs didn't bring those two heads out,'' he said.
''We were working on silage until 10 o'clock [on Wednesday] night and I went to see the shearers about six o'clock [on Thursday morning], so they almost had to have local knowledge of what I was up to.''
It followed a similar incident last year when ewes were stolen from his property, the farmer said.
His property bordered a forestry block and he believed the rustlers might have gained access from there.
''They are not just travelling through. They have gone there for a reason,'' he said.
His property had a surveillance camera and what evidence he had found was passed on to police.
''But it's a big property. You can't have surveillance everywhere.''
Mr Korteweg said the nature of the thefts was alarming.
''The are blatantly taking them, they aren't even trying to cover their tracks, and showing a sign of arrogance towards the law,'' he said.
''Something like that [the ewes' heads] would be pretty distressing to come across, if you owned the stock.''
Rustling strained relations between the rural community and others who, innocently, wanted to use rural areas for hunting and fishing.
It needed to be stamped out, he said.
It was the first incident of rustling in the South Otago area he had heard of, but it followed larger targeted thefts in Central Otago during recent years.
Two Wanaka men faced court in 2011 over the theft of $240,000 worth of stock and farm property and last year Cardrona Valley farmers were told to be aware of rustlers following sheep thefts in the area.
In June last year, 200 sheep died in mysterious circumstances in Ngapara, in North Otago.
Mr Korteweg said all farmers needed to be suspicious of people coming and going from rural properties.
''Get the licence plate number [of vehicles] and it doesn't hurt to ask somebody if they have a right to be there, as well,'' he said.
''Ask `Why are you here?' and see if they have a good reason and, if they don't, take some details and relay this on to the police or the property owner.''
He also advised farmers to lock gates which bordered roads.
Taieri-Clutha area response manager Senior Sergeant Al Dickie said police were investigating the incidents.
No arrests had been made and inquiries were ongoing.
Anyone with information that can help should contact police on 471-4800. Information can also be provided anonymously to the organisation Crimestoppers on 0800 555-111.
People should report anything suspicious immediately on 111.
