California Code, Insurance Code - INS § 12924

(a) The commissioner may issue subpoenas and subpoenas duces tecum for witnesses to attend, testify, and produce documents before the commissioner, on any subject touching insurance business, or in aid of the commissioner's duties.  This process may be served, obeyed, and enforced as provided in the Code of Civil Procedure for civil cases.  A defaulting witness may, upon application by the commissioner to the superior court, be required by order of the court to appear before the commissioner to testify as the court may order.  The court may punish disobedience of its order as a contempt of court.

All the provisions of the Code of Civil Procedure relating to means of production of evidence shall be applicable to any hearing or investigation under this section.  The provisions of this subdivision shall not apply to proceedings required by other provisions of this code to be conducted in accordance with Chapter 5 (commencing with Section 11500), Part 1, Division 3, Title 2 of the Government Code.

(b) A person shall not be excused from testifying or from producing any book, document, or other thing under the person's control upon any hearing or investigation on the ground that the person's testimony, or the book, document, or other thing required, may tend to incriminate the person, or may have a tendency to subject the person to punishment for a felony or misdemeanor; but no individual shall be prosecuted or be subjected to punishment for a felony or misdemeanor for or on account of any act, transaction, matter, or thing concerning which that individual is so compelled, after validly claiming the privilege against self-incrimination, to testify or produce, except for perjury or contempt committed in that testimony.