(a) Witnesses shall receive the following fees:

(1) For attending before any court or grand jury, or before any judge, referee, or commission, $10 per day;

(2) for attending on an inquest, $10;

(3) for each mile necessarily and actually traveled in going to and returning from the place of attendance, mileage at the rate prescribed by law if the distance is more than one mile; and

(4) in criminal cases, reasonable out-of-pocket expenses for food and lodging expenses if authorized by the appropriate county commission.

(b) No witness shall receive per diem or mileage in more than one case covering the same period of time or the same travel, and each witness shall be required to make oath that the fees claimed have not been claimed or received in any other case. No juror shall receive pay as a witness while serving as a juror.

(c) Witnesses shall be entitled to receive, for attending before any attorney general, county attorney or assistant attorney general, under any provision authorizing the officers to compel the attendance of such witnesses, the sum of $10 per day, together with mileage at the rate prescribed by law for each mile necessarily traveled in going to and returning from the place of attendance.

(d) Witness fees shall be paid by the board of county commissioners where the violation of the law being investigated is alleged to have occurred.