HRS §21-3
Rules for setting up legislative investigating committees
This section says that a legislative investigating committee can work during the legislative session and between sessions if the law or resolution that created it allows that. The law or resolution must spell out the committee's purpose, powers, duties, how long it lasts, what it can investigate, and how many members it has.
The statute, as written — Establishment of investigating committees by legislature
(a) An investigating committee may exercise its powers during sessions of the legislature, and also in the interim between sessions when so provided by law or by the concurrent or single house resolution or statute by which the committee was established or from which it derives its investigatory powers. (b) The concurrent or single house resolution or statute establishing an investigating committee shall state the committee's purposes, powers, duties and duration, the subject matter and scope of its investigatory authority, and the number of its members.
LawTrove is not legal advice. The summary above is a computer-generated restatement — the authoritative text is the official version linked above.