Section 66. The colonel of state police, the attorney general or such persons as he may designate, the police commissioner in Boston, the chief of police of any other city, the selectmen of a town or any police officer authorized by any of said officials may at any time enter upon any premises used by any person licensed under section fifty-nine for the purpose of carrying on his licensed business, ascertain how he conducts the same, and examine all second hand motor vehicles or parts thereof kept or stored in or upon the premises, and all books, papers and inventories relating thereto.