Hi there and thank you for your question,
Ya, I thought that you would have an issue getting the police to prosecute this matter.
As far as the police are concerned, the only property that can be maliciously damaged is corporeal property such as desks, computers, doors, vehicles, etc. Software would fall into incorporeal property and can't be damaged in the same way.
I think that the better route to go is to sue the employee for damages that the company will sustain in fixing the problem. If it will cost you R100k to fix the software, or even R100k to re-develop the software, then that would be your damages.
You would need to hire an attorney to sue the ex-employee. You would need to issue a summons and proceed in the Magistrates Court for your damages. You would then need to prove to the court how the damages are calculated.
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