Irradiated tomatoes are on shop shelves, but some customers and even retailers are still unaware that they have been treated.
The Ministry for Primary Industries has changed import health standards to allow treated tomatoes and capsicums. They are treated with gamma rays to kill the Queensland fruit fly.
The tomatoes started arriving about a week ago and any fresh tomatoes from Australia would have been irradiated.
The big supermarket chains say they will not stock them but smaller fruit and vegetable shops and some Asian supermarkets are offering them as a cheaper alternative to Kiwi tomatoes.
Lim Supermarket in Mt Albert labels the tomatoes as Australian and irradiated, and they are about half the price of New Zealand varieties, which are selling for more than $12 a kilo.
Owner Huy Seth said he had been selling irradiated tomatoes and capsicums since last week. He dropped prices on the tomatoes from $9.99 a kilogram to $6.50 this week, but had noticed only household shoppers were buying them.
Those buying in bulk for restaurants were steering clear, Seth said.
"It's because of the requirement that you must say they are irradiated. That put them off. But for householders buying them, they don't mind."
He would continue to stock irradiated vegetables because they were cheaper.
MPI has had two complaints about irradiated tomatoes without proper labelling, one in Auckland and one in Wellington.
Alasdair Macleod, chairman of Tomatoes NZ, said the organisation had received mixed feedback about how well tomatoes were being labelled. He said one of Tomatoes NZ's growers visited the Mangere flea market on Saturday and saw tomatoes from Bowen (Australian) being sold at $8 a kilo. "After some discussion the seller added Australian to his price notice, but apparently refused to put 'irradiated' on it."
An MPI spokeswoman said Turners and Growers, MG Marketing and Freshmax NZ had imported tomatoes or capsicums. All three clearly labelled them as irradiated. But she said sometimes by the time they went to greengrocers or retail markets they were not labelled because retailers were not aware or there were language barriers.
She said MPI was working with the Auckland Regional Fruiterers Association. "ARFAI have provided written information to all their customers, as well as verbal explanations - many of their customers are from Asian businesses. As part of their routine monitoring exercises of customers at markets this week they are following this up."
MPI has also asked its staff and local council environmental health staff to check on retail signs.
Macleod said irradiated vegetables would soon be less of an issue because local supply would come back, pushing prices down.
Fresh World on Dominion Rd is selling Australian tomatoes but a staff member said she did not know whether they were irradiated. "They didn't tell me at the market."
At Simply Fresh, on the North Shore, a shop worker did not realise tomatoes were being imported from Australia.
Price drives purchase choice
Shima Tariqi, Mt Albert, mum of seven
"I bought them. I use them for salads. I wasn't aware (they were irradiated). I think it's healthy and good. I'm very happy, I'm not worried."
Helen Yan, Waterview, mother and the only person who taste-tested an irradiated tomato
"I saw on TV about them. They're a little bit cheaper, everything else is so expensive. We are just looking for the cheapest. I think using chemicals is not healthy, maybe radiation is better than that. They taste no different."
Lovepucet Singh, Papatoetoe, student
"I am worried. I will not buy that because it's not good for the health and I don't like being unhealthy."
Mollie Grace, Devonport, student
"I didn't realise that they were here, but I prefer vine tomatoes. I don't think it's right to treat them, they should grow them naturally. I wouldn't buy them."
Simon Robinson, central Auckland, student
"I probably wouldn't buy them. It just doesn't sound too flash, it doesn't sound appetising. I'd rather buy New Zealand stuff."