Landlord gave house on 50 year lease after selling it to someone

My father had taken a house on lease for fifty years. Subsequently it was detected that before giving lease to my father the owner had already sold the said building to a person who had subsequently sold the same to another person. My father has died and we are staying in other places..Period of lease has also expired. Now the present landlord is constructing multi storied building demolishing the old structure Is the present landlord compelled to give us flats free of cost in the proposed building. as we had once stayed there. If then why. If yes then under which provision. We are Muslims