Health experts say Kiwis travelling to Indonesia should pay close attention to the source of any alcohol they drink, and avoid jugs of pre-made liquor.
Dr Leo Schep, a toxicologist at the National Poisons Centre in Dunedin, said very little pure methanol was needed to have deadly results.
"All you need is half a millilitre per kilogram of body weight, so if you're 80kg, you need 40ml of pure methanol to have a potentially lethal dose."
Dr Schep said physical symptoms were similar to drunkenness and could appear vague at first.
If untreated, the poisoning could lead to rapid breathing, blindness, a coma and seizures which could lead to brain damage.