N.J. Stat. § 43:13-8
An employee of a city of the first class who is retired because of permanent disability received in the performance of his duty, or because of permanent injury or disease, as provided by section 43:13-7 of this title, shall submit himself twice a year, at times to be selected by the pension commission, for a physical examination by a regularly licensed and practicing surgeon or physician designated by the commission. This surgeon or physician shall report back to the commission the physical condition of such employee and whether he continues to be permanently disabled or suffering from permanent injury or disease so as to be entitled to the benefits of this article. If the surgeon or physician reports that the employee's condition has improved so that he is no longer permanently disabled or suffering from permanent injury or disease so as to entitle him to the benefits of this article, the commission may suspend the payment of the pension paid to such employee and order his return to duty, but only after an opportunity is given such employee to be represented by counsel at a hearing on the action of the commission, which hearing shall be conducted in the same manner as where application is made by a municipal employee for retirement because of permanent injury or disease, as provided by said section 43:13-7.
N.J.S. § 43:13-8