Witnesses subpoenaed pursuant to this chapter shall be allowed fees, not less than those paid in the superior court, at a rate fixed by the department, except that an employing unit or a representative or agent of an employing unit subpoenaed to testify or produce books and records under the authority of section 23-675 in connection with that employing unit’s liability under article 5 of this chapter shall not be allowed witness fees or mileage. The fees are deemed a part of the expense of administering this chapter.