The sheriff and his deputies shall be reimbursed out of the county treasury, for actual and necessary traveling expenses, incurred in the performance of their official duties, in addition to the mileage above provided. All claims for reimbursement shall be in writing and shall contain the following information, in addition to such other pertinent information as the county commission may need in order to approve the payment:
I, ______, do solemnly swear, or affirm that the above claim is correct and just; that no part of the same has been paid; that the expense was necessary to the performance of the duties of the office of the sheriff; that payment was made out of my personal funds and that I have not been reimbursed therefor; and that I have not received and will not receive from any source whatever any payment of any part hereof, except as provided by law.
Whenever a claim for reimbursement is made by a deputy, it shall also be approved in writing by the sheriff.
§ 57.360, RSMo