The director may:

(1) Make necessary public or private investigations within or outside of this state to determine whether any person has violated or is about to violate this chapter or any rule or order under this chapter, or to aid in the enforcement of this chapter or in the prescribing of rules and forms under this chapter; or

(2) Require or permit any person to file a statement in writing, under oath or otherwise as the director determines, as to all facts and circumstances concerning the matter to be investigated.

For the purpose of any investigation or proceeding under this chapter, the director or any officer designated by the director may administer oaths or affirmations, and upon his or her own motion or upon request of any party, may subpoena witnesses, compel their attendance, take evidence, and require the production of any matter which is relevant to the investigation, including the existence, description, nature, custody, condition, and location of any books, documents, or other tangible things and the identity and location of persons having knowledge or relevant facts, or any other matter reasonably calculated to lead to the discovery of material evidence.

Upon failure to obey a subpoena or to answer questions propounded by the investigating officer and upon reasonable notice to all persons affected thereby, the director may apply to the superior court for an order compelling compliance.

Except as otherwise provided in this chapter, all proceedings under this chapter shall be in accordance with the administrative procedure act, chapter 34.05 RCW.