(1) A physician designated by the director of public health and 2 other reputable physicians, 1 to be appointed by the department, and 1 by the applicant, shall examine each applicant for a retirement allowance on the grounds of disability, shall determine the extent of the disability, and shall certify the results of their findings to the director of the department of state police and the retirement board, which findings shall be binding upon the director and the retirement board.

    (2) The retirement board may require a person receiving a retirement allowance due to disability to submit to a medical examination periodically. If upon examination it is determined that the person is no longer disabled, the director of the department of state police may order the person to return to active duty. A person who fails to return to active duty following an order to do so by the director of the department of state police forfeits all rights to a retirement allowance under this act unless the person is otherwise eligible to retire.