29. The commission in exercising its powers may by one of its members or any person it designates inquire into any matter of its jurisdiction.
Every member of the commission, and every person so designated, may, in the performance of his duties, enter at any reasonable time the establishment of any person contemplated in section 28, examine his books, records, accounts or other documents and take notes or make copies of them.
Every person having custody, possession or supervision of such books, records, accounts or documents shall disclose them to the investigator on demand and facilitate his examination of them.