N.J. Stat. § 56:8-7
If any person shall refuse to testify or produce any book, paper or other document in any proceeding under this act for the reason that the testimony or evidence, documentary or otherwise, required of him may tend to incriminate him, convict him of a crime, or subject him to a penalty or forfeiture, and shall, notwithstanding, be directed to testify or to produce such book, paper or document, he shall comply with such direction.
A person who is entitled by law to, and does assert such privilege, and who complies with such direction shall not thereafter be prosecuted or subjected to any penalty or forfeiture in any criminal proceeding which arises out of and relates to the subject matter of the proceeding. No person so testifying shall be exempt from prosecution or punishment for perjury or false swearing committed by him in giving such testimony.
N.J.S. § 56:8-7