Each witness who appears before the Legislative Council, the Legislative Oversight Committee, any standing committee, or any special legislative investigative or oversight committee by subpoena of such council or committee, other than a state officer or employee, shall receive for attendance the fees provided for witnesses in civil cases in courts of record and mileage as provided in section 81-1176, which shall be audited and paid upon the presentation of proper vouchers sworn to by such witness and approved by the chairperson of the Executive Board of the Legislative Council.