The commission, the director or other agent or agents designated by the commission may make such public or private investigations within or outside of this state as the commission deems necessary to determine whether any person has violated or is about to violate any provisions of this chapter or any rule or order hereunder, or to aid in the enforcement of this chapter, or to aid in prescribing rules and forms hereunder, and may at any time either prior to or subsequent to the registration of any securities or any dealer or salesman, investigate and examine into the affairs of any person issuing or dealing in or selling or buying or intending to issue, deal in or sell or buy securities or into the affairs of any person when the commission believes that such person is or may be issuing or dealing in or selling or buying securities.