A spa at Auckland's Point Erin Pools will be shut until the new year, after Legionella bacteria was found in the water.
A post on the pools' website says the spa has been treated, emptied, scrubbed and refilled after the bacteria was detected last Tuesday.
Community Leisure Management, who run the pool on behalf of Auckland Council, said it was now waiting on further tests to give the all-clear.
The Ministry of Health says Legionella bacteria can cause Legionnaires - a form of pneumonia with symptoms including coughing, fever, chills, shortness of breath and muscle aches.
But Community Leisure Management says people who used the pool are at minimal risk.