What is Phala Phala farm robbery scandal? What is South African prez Cyril Ramaphosa's role in it?

It is a story that sounds like the plot of a Hollywood thriller. Imagine this a group of robbers break into a farm, what do they discover? Four million dollars in cash, hidden in the furniture but here's the plot twist this money was actually black money that was stashed there so what does the owner of the farm do he recovers some of the loot and instead pays the robbers to keep quiet and here's a even bigger plot twist- the owner of this farm is South Africa's President Cyril Ramaphosa.