Citrus imports from the US have been temporarily halted after fruit fly larvae were discovered in a consignment earlier this week.
The larvae of the spotted wing drosophila were found in a single orange during a routine inspection of a consignment on April 8.
"The fly is a serious pest that could harm a range of fruit crops," said Roger Smith, head of Biosecurity New Zealand.
Smith said the fly is not normally associated with citrus fruit and the ministry's technical experts are assessing the find and any measures that might need to be taken.
"As a precautionary measure, we have put a temporary hold on citrus consignments from the US," he said.