A record number of African rhinos were illegally killed in South Africa this year, driven by the use of their horns in Chinese medicine and a spreading belief in Southeast Asia, unfounded in science, that they may cure cancer. The street value of rhinoceros horns has soared to about $65,000 a kilogramme, making it more expensive than gold. South Africa, home to more than 20,000 rhinos, or about 90 percent of all the rhinos in Africa, lost 455 rhinos to poachers, as of Tuesday, to eclipse the 448 killed in all of 2011, the environment ministry said in a statement. Around 15 animals a year were lost a decade ago, showing the impact of rising demand from Asia. The number of rhinoceroses dying unnatural deaths in South Africa, either through illegal poaching or legal hunts, has now reached a level likely to lead to population decline, according to a study by Richard Emslie, an expert in the field. Poaching increased dramatically from about 2007 as a growing affluent class in China, Vietnam and Thailand began spending more on rhino horn for traditional medicine, where it was once used for ailments such as devil possession. About half of poaching takes place in Kruger National Park, the country's flagship park covering an area about the size of Israel, where soldiers and surveillance aircraft have been deployed in recent months to slow the carnage. The park has been the focal point of an arms race as gangs of poachers sponsored by international crime syndicates have used high-powered weaponry, night vision goggles and helicopters to hunt the animals, investigators said. Follow Ynetnews on Facebook and Twitter