Haw. Rev. Stat. § 371-6
In all hearings or investigations conducted by the director of labor and industrial relations, or any of the director's duly authorized subordinates, including a hearings officer appointed by the appeal board under section 371-4, or the appeal board, with respect to any matters cognizable by any of them, each of the officers, and each member of the board, shall have the same powers respecting the administering of oaths, compelling the attendance of witnesses, the production of documentary evidence, and examining or causing to be examined witnesses, as are possessed by a circuit court and may take depositions and certify to official acts. The circuit court of any circuit upon application by any of them shall have power to enforce by proper proceedings the attendance and testimony of any witness so subpoenaed. Subpoena and witness fees and mileage in such cases shall be the same as in criminal cases in the circuit courts. Necessary expenses of or in connection with any such hearings or investigations shall be payable from the funds appropriated for expenses of administration for the department of labor and industrial relations.
No person shall be excused from attending or testifying or producing material, books, papers, correspondence, memoranda, and other records, before the director, the director's duly authorized subordinate, including a hearings officer appointed by the appeal board under section 371-4, or the appeal board, or in obedience to the subpoena of any of them, in any cause or proceeding before them, on the grounds that the testimony and evidence, documentary or otherwise, required of the person may tend to incriminate the person or subject the person to a penalty or forfeiture; but no individual shall be prosecuted or subjected to any penalty or forfeiture for or on account of any transaction, matter, or thing concerning which the individual is compelled, after having claimed the individual's privilege against self-incrimination, to testify or produce evidence, documentary or otherwise, except that the individuals so testifying shall not be exempt from prosecution and punishment for perjury committed in so testifying.
HRS § 371-6
Rules of Court
Oaths, see HRCP rule 43(d).
Subpoenas, see HRCP rule 45.
Hearings, see chapter 91. Oaths, see §§ 1-21, 621-12. Subpoenas, see § 621-1 .