La. Stat. Ann. § R.S. 51:2612

§2612. Right to examine and copy evidence; summoning witnesses and documents and taking testimony; right to counsel; court aid; process; service and return; fees of witnesses
A. In conducting an investigation, the section or its duly authorized employees shall have access at all reasonable times to premises, records, documents, individuals, and other evidence or possible sources of evidence and may examine, record, and copy such materials and take and record the testimony or statements of such persons as are reasonably necessary for the furtherance of the investigation. The section may issue interrogatories to a respondent to the same extent and subject to the same limitations as would apply if the interrogatories were issued or served in aid of a civil action in the state district courts for the district in which the investigation is taking place.
B. The section, on its own initiative, or on application of any party to the proceeding, may issue subpoenas compelling the attendance and testimony of witnesses or requiring the production of documents for examination or copying. Within five days after the service of a subpoena on any person, the person may petition the section to revoke, limit, or modify the subpoena. The section shall revoke, limit, or modify the subpoena if in its opinion the evidence required does not relate to unlawful practices covered by this Chapter, is not relevant to the complaint which is the subject matter of the investigation, does not describe with sufficient particularity the evidence that is subpoenaed, is unduly burdensome or oppressive, or for other good reason. Any member of the section or any agent designated by the section may administer oaths or affirmations, examine witnesses, and receive the evidence.
C. Witnesses summoned by subpoena of the section shall be entitled to the same witness and mileage fees as are witnesses in proceedings in state district courts. Fees payable to a witness summoned by a subpoena issued at the request of a party shall be paid by that party.
D. In case of contumacy or refusal to obey a subpoena, the section or other person at whose request it was issued may petition for its enforcement in the state district court for the district in which the person to whom the subpoena was addressed resides, was served, or transacts business.
E. Any person appearing before the section may be represented by counsel.
F. The district court, on application by the section or by the person subpoenaed, has jurisdiction to issue an order revoking, limiting, or modifying the subpoena or conditioning issuance of the subpoena on payment of costs or expenses incurred to comply with the subpoena, if in the court's opinion the evidence required does not relate to unlawful practices covered by this Chapter, is not relevant to the complaint which is the subject matter of the investigation, does not describe with sufficient particularity the evidence that is subpoenaed, is unduly burdensome or oppressive, or for other good reason.
G. Complaints, orders, and other process and papers of the section or the agent of the section may be served either personally or by certified mail or by commercial courier as defined in R.S. 13:3204(D), when the person to be served is located outside of this state. The verified return by the individual serving the complaints, orders, process, or papers, setting forth the manner of the service, is proof of service. The return post office receipt, if certified and mailed as provided in this Subsection, is proof of service.