'Thousands of elephants are being killed' for ivory
29 December 2011 Last updated at 19:50 GMT
More elephant tusks were seized in 2011 than in any year since 1989, when the ivory trade was banned, international wildlife trade group Traffic has said.
Tom Milliken, the South and East Africa director at Traffic, said that "criminal syndicates" have been moving the ivory to Asia.
Trade in ivory was banned in 1989 to save elephants from extinction. But it has continued illegally because of huge demand in Asia, where it is used to make decorative objects.