Sixty people have fallen ill after drinking water at Moreton Island’s Tangalooma Island Resort was contaminated.
Health authorities are investigating the possibility of the island’s natural groundwater being polluted by sewage or other contaminants.
Dr Kari Javenin from Queensland's Public Health Unit advised guests to only use bottled water as the bacterial infection may not be avoided by boiling.
"Previously we said that it is OK to consume bottled water. That has been upgraded due to further information and toxins present in the water that is not comprehensively or completely destroyed by boiling,” Dr Javenin said.