More tests for hepatitis A in Oamaru have confirmed an extra three cases.
Children and staff at Edna McCulloch Kindergarten were checked through blood tests this week.
The total number of confirmed cases is now six.
The Southern District Health board says it's uncommon in New Zealand, so it's likely to have come from overseas, but are yet to confirm this is the case.
Around 55 people were tested.
According to the World Health Organization the disease can cause "mild to severe illness", but is rarely fatal. Survivors usually gain lifelong immunity.