It is mainly used for making ornamental carvings and jewellery. Traditionally the elephant tusk was hollowed out and used as an instrument or a horn.

In Europe, ivory was inlaid into to furniture, sculpted into combs and brooches, and used as the favoured material for piano keys. Ivory exports from Africa peaked in about 1900 - at the height of colonisation.

But demand for ivory is also strongly entrenched in Asian culture. China, Taiwan and Hong Kong have had major ivory carving industries for hundreds of years.

In Japan - which remains one of the world's major consumers of ivory - the substance is used for making traditional personal seals called hankos.

Ivory is also a vital ingredient in Chinese medicines, and ground ivory is sometimes used as an aphrodisiac.

Growing demand

Demand for the elephant tusk continued to grow from the 1940s to the 1980s - when it reached its highest-ever levels.

Carved into chess sets, chopsticks, jewellery and walking sticks, ivory was sometimes seen as a hedge against rising inflation.

The availability of automatic weapons and widespread government corruption meant that ivory could be produced in ever-greater quantities.

Although Hong Kong and Japan have dominated the consumer market for raw ivory for decades, demand for the finished ivory goods was fairly high in the West until the trading ban was introduced in 1989.

Ten years ago, the United States was one of the largest importers of worked ivory (valued at $11.8m annually), behind Japan (which accounted for 38% of trade) and the European Community (accounting for 18%) . The United States was buying 16% of the world's worked ivory.

But as the demand grew, the numbers of African elephants began to dwindle.

Following an environmental outcry, alternatives to ivory were sought out. Piano keys began to be made of plastic. And ivory trinkets and jewellery became virtually taboo in many Western countries.

Before the international ban in 1989, raw ivory was fetching somewhere between £60 -£90 per lb. But the price has now plummeted to about £6 per lb.