Haw. Rev. Stat. § 96-10: Powers.

Subject to the privileges which witnesses have in the courts of this State, the ombudsman may:

(1) Compel at a specified time and place, by a subpoena, the appearance and sworn testimony of any person who the ombudsman reasonably believes may be able to give information relating to a matter under investigation; and

(2) Compel any person to produce documents, papers, or objects which the ombudsman reasonably believes may relate to a matter under investigation.

The ombudsman may bring suit in an appropriate state court to enforce these powers.