The same day they began to withdraw all Choice brand strawberries from stores and issued a media statement about the discovery.
The company also agreed to cut up all withdrawn strawberries to see if more needles were found, at the request of MPI.
An MPI spokesman told the Herald this had been completed and no further needles had been found.
New Zealand consumers who have bought Australian Choice brand strawberries are advised to return them.
Police said the person who reported the incident was not harmed as the needles were found before anyone had eaten them.
The incident follows more than 100 reports of fruit being tampered with across Australia.
Timeline of the strawberry sabotage
Sunday, September 23, 3.55pm - Woolworths NZ informed MPI of the findings of three needles in three strawberries from one punnet. Confirmation that police have been informed. MPI requests details.
Sunday, September 23, 4pm - Woolworths NZ initiates withdrawal of all Choice brand strawberries in all Countdown stores who stock them.
Sunday, September 23, 4.20pm - MPI requests additional information from Woolworths.
Sunday, September 23, 4.36pm – Woolworths NZ sends MPI summary of situation and photos. Confirmation in writing that Police have been informed.
Sunday, September 23, 4.40pm – MPI assessment of information provided.
Sunday, September 23, 5.47pm – Woolworths NZ informs MPI that it has issued a press release.
Sunday, September 23, 6.20pm – Woolworths NZ agrees to MPI direction of destruction testing (cutting up all withdrawn strawberries to determine if any needles are present).
Sunday, September 23, 7pm - MPI informs Australian authorities.