La. Revenue and Taxation § 47:2606
For the purpose of determining the correctness of any return, determining the amount of tax that should have been paid, determining whether or not the dealer should have made a return or paid taxes, or collecting any taxes under this Part, the secretary may examine, or cause to be examined, any books, papers, records, or memoranda that may be relevant to making such determinations, whether the books, papers, records, or memoranda are the property of or in the possession of the dealer or another person. The secretary may require the attendance of any person having knowledge or information that may be relevant, compel the production of books, papers, records, or memoranda by persons required to attend, take testimony on matters material to the determination, and administer oaths or affirmations. Upon the demand of the secretary, any examiner, or investigator, a court shall issue a subpoena for the attendance of a witness or the production of books, papers, records, and memoranda. The commissioner may also issue subpoenas.
La. Revenue and Taxation § 47:2606