Working freelance without a work permit (Johannesburg)

Hello!
Does anyone know about the legality of working freelance (such as through sites like oDesk) while living in South Africa without a work permit?

Would this be considered OK if one has a permanent US address and is getting paid into a US bank account? Or, because one is living in South Africa, would it still be considered as working illegally...?

I've tried searching online for an answer but haven't found anything that quite answers this.

If anyone has the ability to provide some insight, I would greatly appreciate it!

Thank you.