N.J. Stat. Ann. § 48:4-26

The Director of the Division of Motor Vehicles or his deputy, auditors or investigators shall have power to conduct hearings and to administer oaths to, and to examine under oath, any such owner or operator and the directors, officers, agents and employees of such owner or operator, and as well all other witnesses relative to the transportation business of such owner or operator, in respect to any matter incident to the administration of sections 48:4-20 to 48:4-34 of this Title.