The South African Cabinet decided to stop the development until the ecological consequences of the method -- involving pumping pressurized water, sand and chemicals into the ground to extract the gas -- have been studied, the BBC reported Thursday.
Experts have said the oil activities could affect South Africa's bid to host the world's largest radio telescope.
The Square Kilometer Array telescope, a multimillion dollar project that could begin construction in 2016, requires an absence of radio interference, which the fracking could cause, they say.
"Cabinet has made it very clear that clean environment together with all the ecological aspects will not be compromised," government spokesman Jimmy Manyi said in a statement.
Several government departments would be involved in research into whether the semiarid Karoo region could be damaged by fracking, he said.