Over the past six months, at least four hoggets and three cattle beasts have been shot and left on land leased by Mr Lemm at Florence Hill near Papatowai.
It appeared two of the cattle beasts had fallen off a cliff and on to the beach after being shot, judging from the marks left, he said.
About a week ago, Mr Lemm heard a calf bellowing but did not see anything untoward. A few days later he came across the carcass of a cow.
It had been shot, its throat slit, and hind legs and back steaks removed. The slaughter left the calf motherless.
The bullet would be removed and handed over to police as evidence.
A strop (a tie-down strap) was found nearby, and Mr Lemm believed a quad bike had been used to move the stolen meat.
The shootings had left Mr Lemm several thousand dollars out of pocket, but also angry and frustrated.
Some of the farmland gave access to prime fishing spots - King's Rock and Rainbow Island - and allowed access to hunters who were granted permission.
"It's dangerous because I also give hunters permission to hunt there ... It's a safety issue. Who is around with firearms. Who knows who is out there?"
He said it was common to see spotlighting from the roadside, despite it being illegal. Two nearby farmers had also had deer shot and left on their properties.
Another farmer told him he had issues with people "continually" spotlighting in a paddock with deer in it, despite four residential houses being nearby.
Acting Sergeant Steve Griffiths, of Balclutha, said illegal hunting was an issue across the Southern policing district. Not only did it put genuine hunters' chances of legally hunting on farmland in jeopardy, it put lives at risk.
"These are senseless acts, killing animals for the sheer fun of it. Why would you shoot an animal for fun? This is someone's livelihood."
Police would increase patrols in the area - during the day, night, or weekend, Acting Sgt Griffiths warned.
He advised landowners to contact their local police station or, if they were unavailable, the Balclutha station, as soon as possible after discovering suspicious behaviour or slaughtered animals.
Taking down vehicle details - registration number, make, and model - would also help police, but only do so if it did not put safety at risk.
Offenders could face a range of charges including illegal hunting, theft of an animal, and being unlawfully on property.
