Imaam persists to construct home in Mosque at illegitimate plac

If Imaam (call himself Maulvi) making/influencing group of area resident, and/or committee members, to construct residence in Mosque area at illegitimate place (lawn), even though he knows that this place is against the law. Suitable accommodation already provided to Imaam, but he persists to construct home in Mosque at illegitimate place, what does Islam say?