(a) The department shall have the authority to prescribe, adopt, promulgate and enforce rules and regulations in conformity with this act and relating to any matter or thing pertaining to the administration of the taxes imposed by this act. The department may from time to time alter or amend such rules and regulations in any manner it considers advisable.

(b) The department or any of its authorized agents is hereby authorized to examine the books, papers and records of any taxpayer or supposed taxpayer, including his bank accounts or similar items, in order to verify the accuracy and completeness of any return made, or, if no return was made, to ascertain and assess the tax imposed by this act. The department may require the preservation of all such books, papers and records for any period deemed proper by it, not to exceed, however, six years from the end of the calendar year to which the records relate. Every such taxpayer is hereby required to give to the department or its agent the means, facilities and opportunity for such examinations and investigation. The department is further authorized to examine any person under oath concerning taxable sales by any taxpayer or concerning any other matter relating to the enforcement or administration of this act; and to this end may compel the production of books, papers and records and the attendance of all persons, whether as parties or witnesses, whom it believes to have knowledge of such matters. The procedure for such hearings or examinations shall be the same as that provided by the Fiscal Code relating to inquisitorial powers of fiscal officers.

(c) Any information gained by the department as a result of any return, investigation, hearing or verification required or authorized by this act shall be confidential except for official purposes and except in accordance with proper judicial order or as otherwise provided by law; and any person unlawfully divulging such information shall be deemed guilty of a misdemeanor and, upon conviction thereof, shall be sentenced to pay a fine not in excess of one thousand dollars ($1000) and costs of prosecution, or to undergo imprisonment for not more than one year, or both, in the discretion of the court.

Notwithstanding the foregoing provisions of this subsection, the department may permit the Commissioner of Internal Revenue of the United States, or the proper officer of any other state now or hereafter imposing a tax upon sales of tangible personal property or classes of such property, or the authorized representative of such Commissioner or officer, to inspect any returns or reports of investigations filed or made under the provisions of this act, or may furnish to such Commissioner or officer or his authorized representative an abstract of any such return, or supply him with information concerning any items contained in any such return or report; but such permission shall be granted or such information furnished to such Commissioner or officer only if the statutes of the United States or of such other state, as the case may be, grant equal privileges to the officers of this Commonwealth charged with the administration of this act.