A Gisborne daycare centre has closed following a widespread outbreak of diarrhoea and vomiting.
Thirty-five children and some staff members have been affected by the bug.
Medical Officer of Health, Dr Geoff Cramp, is not yet sure what it is, but it could be a virus, either Rotavirus or Norovirus.
He says the infection has spread to 60 percent of children at the centre over the past three weeks.
The centre will be closed for two days and Health Protection Officers are investigating further.