La. R.S. 47:1545

The collector or any of his authorized assistants may by subpoena compel the attendance of witnesses and production of any books, records, papers, vouchers, or accounts, of any taxpayer or any person who the collector has reason to believe has information pertinent to any matter under investigation by the collector at any hearing held pursuant to the provisions of this Sub-title. The fees of witnesses required to attend any such hearing shall be the same as those allowed to witnesses appearing in the district courts. These fees shall be paid in the manner provided for the payment of other expenses incident to the administration of this Sub-title.