N.H. Rev. Stat. Ann. § 21-I:36

The commissioner of administrative services shall have the power to hold hearings and make inquiries as he deems necessary to carry out his functions and exercise his powers under the provisions of this chapter. For the purpose of such hearings and inquiries, the commissioner of administrative services shall have the power to administer oaths and affirmations, to examine witnesses and documents, to take testimony and receive evidence, and to compel the attendance of witnesses and the production of documents by the issuance of subpoenas.