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Rhino horns sold on black market in Asia

11 February 2014 Last updated at 00:02 GMT

Britain is to play host to a gathering in London in a bid to get an international agreement to stop the illegal trade in wildlife.

The trade is estimated to be worth more than £6 billion a year, with animals dying in great numbers to meet an appetite from unscrupulous dealers supplying people mainly in Asia.

Sue Lloyd-Roberts reports from Vietnam for Newsnight.