Haw. Rev. Stat. § 448-18
In all proceedings before it, the board and each member thereof shall have the same powers respecting administering oaths, compelling the attendance of witnesses, and the production of documentary evidence, and examining witnesses as are possessed by circuit courts. In case of disobedience by any person of any order of the board or of a member thereof, or of any subpoena issued by it or a member, or the refusal of any witness to testify to any matter regarding which the witness may be questioned lawfully, any circuit judge, on application by the board or a member thereof, shall compel obedience as in the case of disobedience of the requirements of a subpoena issued by a circuit court, or a refusal to testify therein.
HRS § 448-18
Rules of Court
Subpoenas, see HRCP rule 45.