A food safety expert believes sewing needles are not the only way people may be trying to sabotage Australian strawberries.

New Zealand supermarkets have stopped selling them after needles were found in strawberries in almost every state.

Police are investigating the apparent act of food terrorism.

Massey University expert Nigel Grigg told Mike Hosking the saboteurs may also have other tricks up their sleeve.

"If somebody is determined then they could go to plastic, bodily fluids or even dangerous material."

LISTEN ABOVE AS NIGEL GRIGG SPEAKS TO MIKE HOSKING