A punnet of Australian strawberries containing needles was found in an Auckland supermarket on Sunday, the first reported case in New Zealand after incidents in Australia.
In response, Countdown withdrew the Choice brand of strawberries, which were sold nationwide, from shelves and police said they were investigating the incident.
Acting Prime Minister Winston Peters said yesterday all Australian strawberries would now be subject to a screening process across the Tasman before reaching New Zealand supermarket shelves.
Speaking to reporters at the Prime Minister's weekly post-cabinet press conference while Jacinda Ardern is in New York, Mr Peters said there would be ''no more strawberries coming into this country without [them] all being screened, into the future.''
Across the Tasman, Queensland police are leading an investigation into the source of the needles after contaminated strawberries were found in six Australian regions.
Countdown is offering a full refund for any Choice strawberries returned to its supermarkets.
Asked if Countdown was considering extra security in stores or scanning of strawberries, a spokeswoman said the chain was ''talking with our suppliers and produce teams about precautionary measures but we will not be discussing these, for obvious reasons''.
Waimate strawberry grower Jackie Butler, of Butlers Fruit Farm and Cafe, extended her sympathies to Australian growers faced with plummeting demand from a spooked public.
''I feel very, very sorry for them ... it's disastrous for them.''
Ms Butler, who has been growing strawberries for nearly 50 years, said she did not fear contamination as she sells all her own produce.
Strawberry Growers New Zealand research representative Geoff Langford, of Tai Tapu, said needle contamination was an Australian issue and there was no evidence to suggest any connection to New Zealand strawberries.
However, there had been talk from some growers that they might need to use scanners to check strawberries to give customers peace of mind, he said.
Mr Langford said he had no idea what could be driving the needle contamination attacks.
''It's beyond my comprehension. I've never understood idiots.''
University of Canterbury professor of sociology Greg Newbold said it was likely to be a ''copycat situation''.
''It has become a bit of a fad. Somebody has seen they can get publicity, become famous for an afternoon. As long as hysteria is generated, it will keep feeding into the problem.
''It creates panic and they get a reaction ... It can make them feel important in their mostly insignificant lives.''
In a statement, Minister of Agriculture Damien O'Connor said Australian authorities had decided to impose metal detection screening of all strawberry exports.
New Zealand Police have confirmed an investigation is under way concerning the Countdown sabotage, but Detective Superintendent Tim Anderson said it is still too early to comment in any detail.
He is asked the public to contact police immediately if anything suspicious was found in food products.
Mr O'Connor asked New Zealanders not to overreact, as it is ''just one punnet of strawberries where some idiot has put something into it''.
NZ Food Safety and the police were now conducting an inquiry into finding ''the idiot who did this''.
''We're really concerned about all food safety issues and clearly this is a criminal act more than a food safety act.''
- Additional reporting NZME
