A 70-year-old man using thermal optical equipment has been arrested for poaching livestock in Darfield, just inland from Christchurch.
Police said they were aware of incidents of poaching on private properties and have been working hard to locate and hold poachers to account.
They managed to find the offender by testing unique markings on bullets extracted from animals.
That led them to a 70 year old man who has been summoned to appear in court later this month on charges of ill-treatment of animals, theft of livestock and the reckless discharge of a firearm.
Senior constable Hamish Caird said there were serious repercussions for poachers, with the penalty being a maximum $100,000 fine, plus up to two years in prison.
"Unlawful hunting puts other people who may be in the area at risk and could have potentially fatal consequences, poaching can also be a catalyst for other crimes, such as damaging machinery and the theft of fuel."
Rural property owners should make security a priority, keep in contact with their neighbours and let one another know if they saw anything unusual, he said.