Haw. Rev. Stat. § 125-6
The governor and the governor's authorized representative may make investigations and surveys for the purpose of ascertaining facts to be used in administering this chapter, and in making the investigations and surveys, may require the making, filing, or keeping of applications, schedules, records, reports, or statements, under oath or otherwise, administer oaths, take evidence under oath, subpoena witnesses, and require the production of books, papers, and records. Witnesses shall be allowed their fees and mileage as in cases in the circuit courts. The circuit court of any circuit or judge thereof may enforce by proper proceedings the attendance and testimony of any witness subpoenaed to appear within the circuit, or the production of books, papers, and records.
HRS § 125-6