Cal. Government Code § 11187

(a) Except as provided in subdivision (c), if any witness refuses to answer any interrogatory or to attend or testify or produce or permit the inspection or copying of any papers or other items described in subdivision (e) of Section 11181 required by subpoena, the head of the department may petition the superior court in the county in which the hearing or investigation is pending or the county in which testimony is designated in the subpoena to be given or documents or other items are designated in the subpoena to be produced, for an order compelling the person to answer the interrogatories or to attend and testify or produce and permit the inspection and copying of the papers or other items required by the subpoena before the officer named in the subpoena. (b) The petition shall set forth all of the following: (1) That due notice of the time and place for answering the interrogatories or testifying or the attendance of the person or the production of the papers or other items described in subdivision (e) of Section 11181 was given. (2) That the person was subpoenaed or required to answer interrogatories in the manner prescribed in this article. (3) That the person failed and refused to answer the interrogatories or to attend or testify or produce or permit the inspection or copying of the papers or other items required by subpoena before the officer in the cause or proceeding named in the subpoena, or has refused to answer questions propounded to him or her in the course of the investigation or hearing. (c) If the witness named in the subpoena does not reside or conduct business in this state, the department head may seek to compel the witness’ testimony and production, inspection, and copying of documents or other items described in subdivision (e) of Section 11181 in the manner provided for the enforcement of a deposition notice to a nonparty as described in Section 2026.010 or 2027.010 of the Code of Civil Procedure or in any other manner authorized by any law. (d) If any witness objects and based on that objection refuses to answer any interrogatory or to attend or testify or produce or permit the inspection or copying of any papers or other items described in subdivision (e) of Section 11181 as required by a subpoena, the witness shall state the objection and the validity of the objection shall be determined exclusively in a proceeding brought by the head of the department to compel compliance as provided in this section.