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.