In any hearing before the commissioner under section 270C.92, the commissioner shall, upon the request of a municipality or any other party to the proceedings, issue subpoenas and summon witnesses to appear and give testimony, and to produce books, records, papers, and documents. For the purpose of preparing for and participating in a hearing the municipality shall have access to, and use of, all the data, records, and files of the commissioner pertaining to the property in question. Upon demand of any party a record shall be kept by the commissioner of all evidence offered or received at a hearing, the cost thereof to be paid by the party making such demand.