Authorities in Queenstown, where 23 cases of cryptosporidiosis have now been confirmed, say people should assume flood waters in the town are contaminated with sewage and avoid them. Photo: RNZ / Angus Dreaver
There are now 23 confirmed cases of cryptosporidiosis in the outbreak associated with Queenstown's water supply.
Two more cases have been reported in the past day.
The Southern Medical Officer of Health, Susan Jack, said the source of infection had yet to be identified, but investigations were ongoing.
A boil water notice remains in place.
Dr Jack said due to the weather in the Queenstown area, householders should plan ahead in case of power cuts.
Authorities were warning people to avoid contact with flood waters, which they said people should assume were contaminated with sewage.