Woolworths-owned supermarket chain Countdown on Sunday announced it was removing Choice brand strawberries, imported from Western Australia, from shelves across NZ after an Auckland customer reported discovering needles in their fruit.

The company said it had alerted authorities in Australia while NZ police and government agencies have also launched their own investigations.

It was not yet clear whether the needles had been inserted in Australia or after export, New Zealand Minister for Primary Industries Damien O'Connor told Radio NZ on Monday.

"We hope that it would not be a New Zealander doing a copycat ... these will be the things that will be discovered," he said.

Mr O'Connor said he was looking into whether Australian strawberries had undergone extra scrutiny in recent weeks.

"When we're dealing with these kind of illogical, irrational situations, we do have to look at additional checks. It may be that all the supermarkets should have been checking all the strawberries coming into their shops," he said.

"If there's something simple that can be done ... we should do it, at least in the short to medium term anyway."

Some Kiwi growers had reportedly already been eyeing metal detectors amid fears the contaminations could spread from Australia.

More than 100 reports of tampered fruit are being investigated by police across Australia, many of which are thought to be fake or copycat cases, while the federal government has ramped up penalties for so-called "food terrorists".

Countdown last week announced it had halted imports of Australia strawberries to NZ for the season while competitor Foodstuffs ceased shipping them to its stores.

Australian Associated Press