The Ministry of Primary Industries (MPI) says it had been investigating shocking images of bobby calf cruelty for months before it emerged on television at the weekend.
One of the groups behind the footage says it won't stop until it has caught the world's attention.
A camera placed in the rafters of the Te Kauwhata slaughterhouse by an animal welfare group captured the images – young calves being thrown, kicked and even hit with a baton as they're prepared for slaughter.
"What we exposed was the inherent cruelty to the industry with the fact that cows are removed from their mothers so we can drink milk, but also deliberate vicious cruelty to the animals," SAFE executive director Hans Kriek says.
The footage has not only shocked animal welfare groups, but dairy farmers as well.
They say this and other covert footage, which was shot on or near several Waikato dairy farms, is not acceptable in the dairy industry.
"I don't think this is widespread," DairyNZ CEO Tim Mackle says. "This evidence came to us last week – [the] middle of the week was the first time we saw the footage of this. We were shocked like everybody else and we want to do something about this."
MPI says it launched an investigation when it obtained the footage in September.
"We are going to get to the bottom of this," MPI Deputy Director-General of Regulation and Assurance Scott Gallacher says. "If this appears in court we are going to be seeking the strongest sentences for the people who are responsible for this sort of conduct."
But Mr Kriek says MPI was too slow to act and they plan to take their footage international.
"We know that New Zealand is very sensitive about its international trading reputation, so we are going to talk to consumers of New Zealand dairy," he says. "Ninety-five percent of those happen to be overseas, so we're going to talk to them and that will be a big stick behind the door to making sure the Government and industries do something for those animals."
But Mr Gallacher says every priority is being placed on the investigation and they're still in the process of compiling evidence before looking to take further action.