Dolphin-hunting season is at its peak in Japan and Australian, and Japanese environmentalists have launched legal action in an attempt to end the internationally-condemned slaughters in Taiji.

Every year Japanese fishermen have permission to kill up to 20,000 dolphins and small whales as part of what they say are centuries-old traditions.

Australian environmental group Action for Dolphins has teamed up with a Japanese animal rights organisation, Life Investigation Agency, to challenge the legality of the killings.