Rhino poaching in South Africa has hit a new record high, with 341 of the animals lost to poachers so far this year as black-market demand for rhino horn soars, wildlife group WWF said Thursday.

Poaching deaths have already outstripped last year's total of 333, the previous record, WWF said.

Officials blame the poaching surge on organised crime syndicates selling rhino horn for use in Asian medicinal treatments -- especially in Vietnam, where it is believed to cure cancer.

"In order to save rhinos from extinction, the criminal syndicates operating between South Africa and Vietnam must be uncovered and shut down for good," Joseph Okori, WWF's African rhino programme coordinator, said in a statement.

"Vietnam should follow South Africa's example and start sending poachers, traders, smugglers and sellers to jail."

WWF also confirmed last week that rhinos have gone extinct in Vietnam.

The organisation said the country's last Javan rhino was found shot with its horn removed.

Booming demand has driven the price to half a million dollars per horn, according to the Convention on International Trade in Endangered Species.

South Africa, which lost just 13 rhinos to poaching in 2007, has responded to the surge by dispatching army troops to fight poachers and stepping up arrests.

But it has struggled to stop poaching syndicates that use helicopters, night vision equipment and high-powered rifles to hunt their prey.