No treasurer, or any of his deputies, shall, either directly or indirectly, obtain by contract, purchase, barter or exchange, either for himself or any other person, or become the owner, in whole or in part, of any warrant drawn upon the treasury of his county or city or payable out of such treasury, other than a warrant lawfully payable to such treasurer or deputy. If any treasurer or deputy shall so contract for or purchase any such warrant, such treasurer shall not be allowed in his settlement the amount of the warrant, or any part thereof. This disallowance shall be in addition to the penalties prescribed in § 58.1-3144.