The Ministry for Primary Industries has a nice concise overview about what the requirements for producing, selling and exporting NZ organic products.
The key point about selling organic product in New Zealand is that it must comply with the Fair Trading Act 1986 in respect to using the term 'organic' in labelling and marketing claims. In short, if the product is labelled organic, it must be organic. Otherwise, the product is not being represented accurately and the producer (or supplier) can be prosecuted for not representing the product correctly.
There's
much more information on the MPI site - it's well worth a look if you want to know more about organic food standards in NZ.