If the investigation comes forward and says this is a fraud (ponzi scheme), yes you will owe that money back. It's been discussed several times, you would get a confiscation order from the courts and they would request that money back under proceeds of a crime act.
It's fraudulent money and proceeds of a crime, you don't think the tax man and the police are going to let you have other peoples money and spend it and not pay any tax.. The courts don't care if you've been laid off, you've got fraudulent money..
Look at any recent Ponzi and see how much the authorities redistribute between clients, it's never the full amount (some people go bankrupt etc paying these back)
Where do you think the redistribution of funds comes from? The fairy's in the sky? No, people that have made a significant amount of money pay it back.