Supermarkets are upping security as vegan activists put protest stickers on meat products.
The stickers have messages like, "this package contains the body of someone who did not want to die" and "dairy is scary".
Managers around the country had been warned to watch out for people trying to deface meat products with anti-meat stickers.
Pat, a butchery manager at a Foodstuffs supermarket, said it was a costly and wasteful thing to do.
He said it was affecting locally owned supermarkets, which were having their products destroyed.
However, the Vegan Society said it was a step too far to say putting protest stickers on meat was theft.
Spokeswoman Claire Insley said it was just defacement of property.
She said nothing had been stolen and all the activists had done was put a sticker on some packaging.
Insley said the organisation didn't necessarily agree with the practice but sympathised with those who were doing it.
Beef and Lamb New Zealand chief executive Rod Slater told Mike Hosking it was a minor issue at this stage but police could be called in if it got any worse.
He said it should not be forgotten that it was vandalism.
Slater said the activists were behaving illegally and interfering with the daily lawful activity of retailers.
However, he said most vegans were responsible people and it was a very small splinter group doing this.
Slater doubted people would become vegans after reading the stickers.
Countdown said it appreciated and respected people's rights to their own opinions, but would not condone tampering with food.
A spokeswoman said the chain offered a range of vegan and vegetarian options throughout its supermarkets.
She said Countdown also worked closely with hundreds of local farmers to provide quality meat, and good animal welfare was at the heart of these partnerships.