In administering laws and regulations relative to motor vehicles the secretary and the commissioner may summon witnesses in behalf of the state and may administer oaths and take testimony. They also may cause depositions to be taken and may order the production of books, papers, and documents. The fees for attendance and travel of witnesses shall be the same as for witnesses before the district courts and shall be paid by the state in the same manner as any other expenditure by the departments.
La. R.S. § 32:4