The Ministry for Primary Industries (MPI) said the Pacific fruit fly larvae were detected in a consignment of watermelons during an inspection at the Ports of Auckland on Tuesday.
On Friday, the ministry announced it had temporarily suspended imports of watermelon from Tonga pending an investigation into non-compliance by the Ministry of Agriculture and Food, Forestry and Fisheries in Tonga.
A separate shipment of 29 tonnes of watermelons from Tonga are also being held without clearance.
New Zealand has strict biosecurity measures to stop pests and diseases before they enter the border.
There is no official word yet from Tonga’s Ministry of Agriculture on this matter.