A politician? Prosecuted for fraud? In Poland? Are you kidding me?
Slightly kidding, however immunity can be stripped and once, just once, a Polish government might decide to do something decent that reflects well on their country at an international level rather than just causing distaste and inviting ridicule.
We don't have nearly enough prosecutors, judges and prisons to open this Pandora's box.
In Britain and a few other places there are special prison wings where they put naughty police, prosecutors, judges and politicians both local and national (for their own safety largely). I mentioned this once in Poland and the general consensus was that this was a good idea.
Of course Soviet-style immunity for politicians, prosecutors etc is a PRL hangover that subsequent administrations haven't got rid of. For the obvious reason.
I remember that several years ago the media outside Poland were publishing some fairly scathing articles about Czarnecki's character. AFAIK there was a photograph doing the rounds that was part of that. I suppose we'll see more media coverage if they've run out of Covid/BidenFootball stuff. Unless Russia invades Ukraine in which case it will all be forgotten.