The five youths responsible for filming a video of a kitten being bashed to death with a stone were all aged between 11 and 16 years old, say Invercargill police.
The video was posted online on Facebook by the animal welfare group Paw Justice and has been viewed more than 200,000 times since last night.
It shows young people throwing a large rock at the kitten until it dies.
Southland police said this afternoon that the five youths responsible for the "disturbing" video had been identified, and were all aged between 11 and 16.
Police said the offenders would all be interviewed and referred to the Invercargill Youth Services team for appropriate action.
Three further kittens have also been removed from the home of one of the offenders by police and the SPCA. Those kittens will be checked over and rehomed by the SPCA.
"We recognise that the content of the video has been extremely upsetting for people across New Zealand," said police. "Our staff have also been sickened by the video."
Wilful ill treatment of animals is punishable by up to five years in prison.
Paw Justice co-founder Craig Dunn said it was a tough decison to share the video, but they wanted to highlight the abuse.
"It's one of the worst things I've ever seen and I want to show people and let them know what's really going on in New Zealand.
"There are good pet owners out in the community who love their animals, they don't realise this stuff is happening, so it's a good wake up call."
The video had been watched more than 200,000 times before it was removed this afternoon.
Among the thousands of comments were dozens of death threats and abusive messages towards the teenagers. Some of those included the name and the address of the teenager who is alleged to have thrown the rock.
Netsafe chief executive Martin Cocker said while it was horrific offending, it was not up to animal welfare groups to identify offenders and they should have left it to police.
"If you put up footage of somebody doing something like this you know it's going to incite people online, you know how offensive the material is and you know that some people are not nessessarily going to hold back on what they say or in some cases what action they might take."
Constable chief Chris Wakelin is the sole-charge officer in Ohai and said he was able to easily identify the people involved in the video.
He said the families of those involved did not seem suprised to him on their doorstep.
"Once I explained the impact it had had on the community, and the country as a whole, they were quite upset."
Constable Wakelin said he would like to see those responsible go before the Youth Court.
SPCA Southland manager Richard Hay said welfare officers supported police and later confiscated three other kittens from one of the teenagers' homes.