"On the eastern side you see a pig -- an insulting symbol for our community and our religion -- and other insults," Bronislaw Talkowski, the president of the Tatar community in the village, told a local radio station.
The wooden mosque is in an old Muslim cemetery in the village of Kruszyniany in the east of the country, near the border with Belarus.
"It is hard to say who is behind it but it is certainly an organised group," Talkowski added.
One line of inquiry is over whether the attack was linked to a row over types of ritual slaughter used by the Jewish and Muslim communities, which have been banned since January, with a new vote in parliament and a constitutional court hearing on the issue due shortly.