New Jersey § 2a:81-17

§ 2a:81-17.

In any criminal proceeding before a court or grand jury, if a person refuses to answer

a question or produce evidence of any other kind on the ground that he may be incriminated

thereby and if the Attorney General or the county prosecutor with the approval of

the Attorney General, in writing, requests the court to order that person to answer

the question or produce the evidence, the court shall so order and that person shall

comply with the order. After complying and if but for this section, he would have been privileged to withhold

the answer given or the evidence produced by him, such testimony or evidence, or any

information directly or indirectly derived from such testimony or evidence, may not

be used against the person in any proceeding or prosecution for a crime or offense

concerning which he gave answer or produced evidence under court order. However, he may nevertheless be prosecuted or subjected to penalty or forfeiture

for any perjury, false swearing or contempt committed in answering, or failing to

answer, or in producing, or failing to produce, evidence in accordance with the order. If a person refuses to testify after being granted immunity from prosecution and

after being ordered to testify as aforesaid, he may be adjudged in contempt and committed

to the county jail until such time as he purges himself of contempt by testifying

as ordered without regard to the expiration of the grand jury; provided, however,

that if the grand jury before which he was ordered to testify has been dissolved,

he may then purge himself by testifying before the court.