The incident has cast a dark shadow over the popular tourist destination, sparking urgent questions about safety standards and the dangers lurking in counterfeit drinks.
According to reports a fight had broken out between two men, but after police intervened, the situation appeared resolved, until the next morning.
Police in New Zealand searching for missing British backpacker, Grace Millane, say concerns are growing for her safety after she vanished.
Two Finnish backpackers were attacked on a popular hiking trail in Western Australia, by a man who is clearly a few beers short of a six-pack.