Hidden assets in Poland - how to legally find them?

Question, If you wanted to find proof of inherited property in Poland, what is the legal way of find such information? Is it possible to track inherited assets via the Land Registry of Poland?

My mother married a Canadian man who inherited a significant amount of property and bank accounts from their deceased relative. Some of the property was sold immediately, some is still owned. They are now embroiled in a divorce and my mother's husband is denying/hiding the inheritances he has received. Is there a legal way that my mother can prove the inheritances? Are inheritances registered in court and are they accessible by the public? Can a person obtain a copy of all property and assets received by an individual?

Any suggestions. If you were trying to prove someone obtained property and assets in Poland, how would you go about it?

Is it legal to dispute inherited property in divorce cases in Canada?One good reason I made a estate and only named the inheritors to benefit and never to be in dispute with there spouses about it.

Maybe you should hire a detective in Poland to do the job then doing it yourself if you think its worth it.

My mother is not interested in the property, however she is interested in proving that her husband isn't completely "broke" as he is suggesting. He would have inherited money in accounts as well as multiple properties.