If any treasurer or deputy shall sell or assist in selling any real property, knowing the same to be not subject to taxation, or that the taxes for which the same is sold have been paid, or shall knowingly and willfully sell, or assist in selling, any real property for the payment of taxes to defraud the owner of such real property, or shall knowingly execute a deed for property so sold, he shall be deemed guilty of a Class I misdemeanor and shall be liable to pay the injured party all damages sustained by such wrongful act, and all such sales shall be void.
Neb. Rev. Stat. §§ 77-1816