a. If any person in attendance pursuant to a subpena or interrogatory issued pursuant to this act refuses to answer personally a question or produce evidence of any kind, or make the required answers on the ground that he may be incriminated thereby, and if the Attorney General, in a writing directed to that person, orders that he answer the question or produce the evidence, the person shall comply with the order. After complying therewith and if, but for this section, he would have been privileged to withhold the answer given or the evidence produced, that answer, testimony or evidence or any evidence directly or indirectly derived therefrom, may not be used against him in any prosecution for a crime or offense concerning which he gave answer or produced evidence; provided that the answer, testimony or evidence is responsive to the question propounded. That person may, however, be prosecuted or subject to penalty or forfeiture for any perjury, false swearing or contempt committed in answering, or failing to answer, or in producing evidence or failing to produce evidence or failing to do so in accordance with the order.
b. If any person fails to obey the command of the subpena after being ordered to do so by a court of competent jurisdiction, he shall be guilty of a crime of the fourth degree. In the alternative, if a person shall fail to obey the command of a subpena after being ordered to do so by a court of competent jurisdiction, the Attorney General may apply to that court to adjudge the person in contempt and to commit him to jail until such time as he purges himself of contempt by responsively answering, testifying or producing evidence as ordered.