Another case of Legionnaires disease has been confirmed in Auckland.
A Middlemore Hospital spokeswoman said a patient was diagnosed as having the disease today.
Twelve people have needed hospital treatment for the fatal lung infection in the past six weeks, one of whom died.
The average number of cases in the Auckland region is typically one or two every six weeks.
It's believed around 300 buildings in the city are affected by the disease, which can be caught from contaminated air-conditioning systems, domestic shower heads, spa pools and compost mix.
The outbreak has prompted public health officials to urge owners and managers of buildings that contain air-conditioning cooling towers, or industrial processes that use water and generate aerosols, to 'shock-dose' them, by using a biocide to eliminate the Legionella bacteria.
Medical officer of health Dr Simon Baker said because of the severity of legionnaires' disease, it was important that building managers acted quickly.