N.J. Stat. § 34:13-5
Witnesses shall be examined on oath or affirmation which oath or affirmation the chairman of the board is empowered to administer. A majority of the board may provide for the examination and investigation of books, documents and accounts pertaining to the matters in dispute and belonging to either party. The board may unanimously direct that instead of producing books, papers and accounts before the board, an accountant agreed upon by the entire board may be appointed to examine such books, papers and accounts, and such accountant shall be sworn well and truly to examine such books, documents and accounts as may be presented to him, and to report the result of his examination in writing. Before the examination, the information desired and required by the board shall be plainly stated in writing and presented to the accountant, which statement shall be signed by the board. Attorneys at law or other agents of either party to the dispute shall not be permitted to appear or take part in any of the proceedings of the board, but the same shall be, as far as possible, voluntary.
N.J.S. § 34:13-5