For the purposes of section forty, the commissioner or the person making the examination shall have free access to the vaults, books and papers of any such foreign bank and out-of-state bank, and may summon the directors, officers or agents thereof, and such other witnesses as deemed necessary for examination relative to the affairs, transactions and condition of such banks, and for that purpose is empowered to administer oaths.
Mass. Gen. Laws ch. 167, § 41