An investigating committee may exercise its powers: when the General Assembly is in session; and when the General Assembly is not in session, if the investigating committee is authorized to do so: by law; by the resolution that establishes the investigating committee; or by the law or resolution from which the investigating committee derives its investigatory powers. An investigating committee shall adopt rules that govern its procedures, including the conduct of hearings. The rules may not be inconsistent with law or any applicable rules of the General Assembly.