Is this European(western), Eastern(northern) or another Hedgehog?
I think the picture you have is not enough to make a proper distinction between the two species. 

By this site, they found some morphological characteristics to make the distinction but: 


You have to carefully take pictures of the animal parts 
The study nearer Poland has been made in Estonia and those characteristics could be slightly different in other countries.


I did not find another documents about hedgehog populations in Poland but the wikipedia page says both species are living in the country.