Sec. 1.06. OTHER PENSION SYSTEM ESTABLISHED BY STATE LAW. Notwithstanding any other law, if the employees of the fire or police department who have been members of the fund are included in another pension system established by state law, the board shall act for any similar board created by that law with regard to the receipt and payment of amounts owed to the employees under this Act. Employees of a department who are members of the fund and are not included in the other pension system may not participate in any payment under this section.