International wildlife trade group Traffic says more elephant tusks were seized in 2011 than in any year since 1989, when the ivory trade was banned. The group said elephants have had a horrible year, with 23 tonnes of ivory seized, representing at least 2,500 dead animals.

Trade in ivory was banned in 1989 to save elephants from extinction. But it has continued illegally because of huge demand in Asia, where some believe ivory has medicinal properties. This is despite ample scientific evidence to the contrary.

A statement from Traffic, which monitors the trade in wildlife products, said most illegal shipments of African elephant ivory end up in either China or Thailand. The group said there had been at least 13 large seizures of ivory this year, compared to six last year.