It looks like a moment of terror - a diver finds her leg clamped in the jaws of a beluga whale. In fact, it was a stunning example of an animal coming to the rescue of a human life.
Yang Yun, 26, was taking part in a free diving contest without breathing equipment among the whales in a tank of water more than 20ft deep and chilled to Arctic temperatures.
She says that when she tried to return to the surface, she found her legs crippled by cramp from the freezing cold. At that point Mila the beluga took a hand, or rather a flipper.
