I. The department, or any deputy, employee or agent authorized by it, is hereby given the authority to examine, during the usual business hours of the day, the records required to be preserved under this subdivision; provided, however, that no distributor, user or transporter shall be subjected to unnecessary examinations or investigations.
II. The commissioner shall have the power, in the enforcement of the provisions of this subdivision, to hold hearings, to administer oaths to witnesses, to take the sworn testimony of any person and cause it to be transcribed into writing, and for such purposes shall be authorized to issue subpoenas and subpoenas duces tecum and compel the attendance of witnesses, and shall have the power to conduct such investigations as he may deem necessary; provided, that it shall be unlawful for any person to disclose the information acquired by the department or any of its agents under the provisions of this section, except when used by the state or any officer thereof in any proceeding for the collection of the road toll or any prosecution for violation of any of the provisions of this subdivision, and provided, further, that if any distributor, user or transporter shall refuse access to such records or if any person shall fail or refuse to obey such subpoena or subpoena duces tecum, or shall fail or refuse to testify before the commissioner, then the commissioner may petition the superior court setting forth the circumstances, and the court shall enter such order against such distributor, user, transporter or person on the premises as the enforcement of this subdivision and justice shall require.