La. Revenue and Taxation § 47:1482
The board is authorized to make such examination and investigation as it may deem necessary to determine the correctness of any claim presented; and for that purpose, the board is authorized to employ any expert accountant or clerical assistants that might be necessary. The board may appoint an agent to conduct any investigation, in Louisiana or elsewhere, that may be found necessary in discovering the facts in connection with any claim. The board is authorized to require the claimant to present for the board's inspection all books, papers, documents, receipts, etc., that may have a bearing upon the true facts in connection with any claim presented; and the burden of proof shall always rest with the person presenting any claim against the state for any purpose whatsoever. The board is further authorized to call upon any department or official of the state government or any institution thereof or any citizen to make available to the board any and all information, documents, receipts and papers that will aid it in discovering the correctness and justice of any demand or claim that might be presented to it against the State of Louisiana.
La. Revenue and Taxation § 47:1482