N.J. Stat. § 43:21-51
In any proceeding had as the result of a complaint filed with the commission as provided in this article, the hearing officer may (i) if an award of benefits is made to an employee, allow a reasonable fee, not exceeding twenty per centum (20%) of the amount of the award, to the attorney, if any, representing the employee, payable by the employer or insurer, and (ii) allow reasonable appearance fees to medical witnesses, the payment of which may be assessed wholly or in part against the employee, the employer or the insurer as the hearing officer shall determine. Except for amounts thus allowed, it shall be unlawful for an attorney or any other person to ask for, contract for, or receive, directly or indirectly, any charge for services in securing or attempting to secure any benefits hereunder, or for a medical witness to make any charge for an appearance at a hearing held pursuant to this act.
N.J.S. § 43:21-51