Although a rhino horn is made mainly of keratin, the key structural component of hair and nails, a belief by Vietnamese people that rhino horn can cure diseases has put the rhino populations at risk, according to Care for the Wild International (CWI).
Director Mark Jones of CWI said on the organization's website he had seen prices quoted as high as US$60,000 per kilogram for powdered rhino horn in Vietnam.
In Asia, rhino horn is rumored to be able to cure anything from headaches to gout, fevers to rheumatism; therefore, rhino horn is used as a component for traditional medicines.
Jones added rumors in Vietnam boasted that rhino horn can cure cancer, which has led to a huge increase in demand for rhino horn products in the country.
Most of the horn is coming out of Southern Africa, according to Jones, and the major markets for powdered rhino horn are Vietnam and China.
However, illegal traders usually route the horns through other countries in Asia or even Europe as they try to evade the law, he said.
According to CWI, there are five species of rhino left in the wild with around 26,000 rhinos still living across Africa and Asia.
By far the most numerous, the southern white rhinos, live mainly in reserves and game parks in South Africa. Other species - the black rhino in Southern and Eastern Africa, the greater one-horned rhino in India and Nepal, and the Sumatran and Javan rhinos in Southeast Asia - are threatened with extinction.
Only around 300 Sumatran rhinos and as few as 45 Javan rhinos, are thought to remain.
Last year, South Africa alone lost at least 333 rhinos to poachers, almost three times the previous year, Jones said.
In April 2010, a rare Javan rhino, suspected of being the last of its kind in Vietnam, was found dead in Vietnam's Cat Tien National Park.
Conservationists believed the rhino was shot in the leg by poachers probably two or more months before it died.