Beekeepers say the existence of another deadly bee pest here could put New Zealand's besieged honey bee population under even more pressure.
MAF Biosecurity has confirmed the presence of the parasite Nosema ceranae in hives on the Coromandel Peninsula.
The highly infectious parasite infests the gut of bees, killing them and wiping out hives. It is easily spread by the movement of bees or by beekeeping equipment.
The organism is one of the pests, like the varroa parasite, that's been linked to colony collapses overseas.
National Beekeepers' Association joint chief executive Daniel Paul says if it became widespread it could have serious consequences.
Mr Paul says beekeepers' concerns about New Zealand's biosecurity system have been reinforced. Beekeepers have fought the ministry since 2006 to prevent the import of Australian honey and honey products, which they say could carry pests and diseases.
MAF carries out more tests
Ministry spokesperson Jeremy Lambert says, however, that it is not yet clear how or when the parasite arrived, because the technology to test for it has only recently become available.
Mr Lambert says Nosema cerenae has been found in every country that has ever used the new test.
MAF Biosecurity's team manager of animal response, Andre van Halderen, says MAF will do further tests to see how widespread the parasite is and how long it may have been in New Zealand.
The results of the testing should be known by the end of next week.