A formal investigation begins with the issuance of an order signed by the Comptroller. The order must designate the person or persons empowered by the Comptroller to conduct the investigation. These persons are authorized, among other things, to administer oaths and affirmations, to take or cause to be taken testimony under oath, and to issue or modify subpoenas, including subpoenas duces tecum, as to any matter under investigation by the Comptroller. Upon application and for good cause shown, the Comptroller may limit, modify, withdraw, or terminate the order at any stage of the proceedings.