No warrant for the payment of any claim shall be issued by the Finance Director unless such claim shall be evidenced by a voucher approved by the head of the department for which the indebtedness was incurred and countersigned by the City Manager. Before issuing such voucher, the supplies and materials delivered, or work done, shall be duly inspected and certified to by the head of the proper department or office, or by a person designated by him or her. The head of each department or office shall require proper time reports for all services rendered to be certified by those having cognizance thereof, to serve as a basis for the preparation of payroll vouchers. Each head of a department and his or her surety shall be liable to the City for all loss or damage sustained by the City by reason of the negligent or corrupt approval of any claim against the City in his or her department. Prior to drawing of a warrant for the payment of any voucher or claim, the Finance Director may at his or her discretion cause an investigation or inspection to be made by a person designated by him or her. (Amended 11-7-89)