A further three locations in Taranaki have tested positive for myrtle rust infection today according to a statement from the Ministry for Primary Industries (MPI).
Two are residential gardens and the third is a Taranaki Regional Council-run plant depot, which supplies plants to farmers for riparian planting.
The riparian plant depot concerned has been closed and is under treatment.
There are four other similar plant depots in Taranaki and movement of plants from these sites has been restricted while investigations continue.
This brings the total number of known affected properties to eight, with two in Kerikeri, Northland, four in the Taranaki region and a further two in New Plymouth.
MPI says they expect to continue to find new locations of infection given the most likely scenario is that the fungal spores entered New Zealand from Australia during a major wind event.
Myrtle rust attacks native trees, such as pohutukawa and rata, and could cause serious damage to manuka trees, used in honey production.
There is no known method for controlling it in the wild, other than applying fungicide in very small areas.
More than 100 government staff are working to contain the spread, and have been handed a blank cheque for their mission.