New Zealand could do more to protect against needles in fruit, but it would come at a cost.

A criminal investigation has been launched after a needle was found in a punnet of New Zealand strawberries in Canterbury.

It follows a needle also being found in a capsicum sold from Tauranga Countdown.

Massey University Quality Systems professor Nigel Grigg told Mike Hosking it's hard to know where in the chain the contamination happened.

"One option on the table is shrink wrapping fruit, which happens in a number of Asian markets."

When asked if he believed this was a copycat situation after what happened in Australia a few months ago, Grigg said it was almost certainly the case.

"Yes, it does look that way. We may have a few isolated incidents, but there is no evidence there is anything in particular about strawberries which show they are the only product targeted."

LISTEN ABOVE AS NIGEL GRIGG SPEAKS TO MIKE HOSKING