RHINOS could become extinct in the wild within two decades, according to researchers who point to the illegal trade of the animal's horn as the main threat.
By weight, rhino horn is now more valuable on the black market than gold, diamonds or cocaine.
Trade in rhino horn was banned in 1977 but not everyone is convinced the tactic designed to protect the animal has worked. Last year poachers killed 668 rhinos in South Africa - double the number killed in 2010.
In a paper published in Science on Friday, two Australian researchers call for the legal trade of rhino horn. Harvested from live animals kept on private conservation reserves, they argue this is the only way to turn things around.
Duan Biggs and Hugh Possingham from Queensland University say the trade ban has failed because it has artificially restricted supply, which has seen blackmarket prices soar and poaching activity flourish.
On average, rhino poaching in South Africa has more than doubled in each year over the past five. If the trend continues, Dr Biggs, a conservation economist, believes the wild rhino faces extinction within two decades.
"There is that risk," Dr Biggs said. "It is not overstating things. What is likely to happen is that as rhinos become very few, people will put them in small, heavily guarded, heavily fortified encampments to protect them which is effectively placing them in captivity."
While conceding that some will oppose the idea in favour of strengthening awareness and anti-poaching campaigns, Dr Biggs said the evidence over the past 30 years suggested those approaches had failed.
With colleagues from France and Zimbabwe, the Australian researchers estimate that 5000 white rhinos would be enough to meet demand for the horn, which is used in dagger handles in Yemen and traditional Chinese medicine.
Because rhino horn is made of keratin - the key structural component of hair and nails - it regrows.
"Harvesting the horn would have a minimal impact on the animal and if well managed and well regulated, it's a perfect product for sustainable use," Dr Biggs said. "The horn regrows and can be harvested from an animal every three to four years."