The BVI would need to be registered in ZA as a external company firstly before it can buy property. Secondly you will have to pay CGT. In fact when selling and where property is valued at more than R2m a 7.5% provisional CGT withholding tax is applied and paid to SARS.
However if you are merely transferring ownership of the shares of the BVI to the new owner and the BVI remains owner CGT may be circumvented but I doubt it. Speak to a good tax advisor on that part.