The number of cryptosporidium cases in Queenstown has risen by one in the past 24 hours.
Dr Susan Jack, Medical Officer of Health, said there were 61 confirmed cases today, 15 probable cases, and 19 under investigation.
There were 60 confirmed cases yesterday.
Dr Jack said a source of infection still had not been identified.
The news comes as a boil water for many in the resort town could have their boil water notice lifted by tomorrow.
The Queenstown Lakes District Council said yesterday it planned to isolate the Kelvin Heights water treatment plant, which would allow the boil water notice to be lifted for those on that supply including Frankton, Kelvin Heights, Quail Rise and Hanley's Farm.
The council's records suggest more than 3600 residents in Frankton alone would be affected by the change, which does not include visitors in the area.
