Cal. Lab. Code § 6613
The appeals board, a hearing officer, or any party to the action or proceeding, may, in any investigation or hearing before the appeals board, cause the deposition of witnesses residing within or without the state to be taken in the manner prescribed by law for like depositions in civil actions in the superior courts of this state under Title 4 (commencing with Section 2016.010) of Part 4 of the Code of Civil Procedure. To that end the attendance of witnesses and the production of records may be required. Depositions may be taken outside the state before any officer authorized to administer oaths. The appeals board or a hearing officer in any proceeding before the appeals board may cause evidence to be taken in other jurisdictions before the agency authorized to hear similar matters in such other jurisdictions.
Ca. Lab. Code § 6613