Polar bears are distinguishable by their snow-white fur. But a baffling sight awaits visitors to the Singapore zoo: the coat of the bulky Arctic beasts housed there have taken on a bright green hue.

Initial speculation about the animal being spray-painted to camouflage it was scotched, with the zoo spokesperson revealing that the green colouring has been caused by an algal presence. But the algae, which has made the bear's translucent hair shaft its home, is reported to be harmless. Even as hydrogen peroxide solution has been effective on the fur of a mother bear, its cub will have to endure the green splodges on its back, legs and ears until it is treated.