yes, I'm sure
And you're certain, how?
The ducks' father was a clear commie collaborator. Something generously glossed over by the PIS/Nasz Dziennik crowd. As far as I know, IPN has not published any files relating to him. By the way, IPN was offered by the government two alternative locations to their present offices.
What's the problem then?
And yes, he was a clear collaborator. His rather rapid rise, including lectures to the Party cadre could only have been as a result of some very severe collaboration.
I suspect when the current generation retires from politics, we're going to find some very nasty things out about the Kaczynski family.