Notwithstanding any other law to the contrary, if a former member of any pension fund or retirement system, contributory or noncontributory, established under any law of this State, who has been granted a pension or retirement allowance for any cause other than vesting or deferred retirement, becomes employed again in a position which makes him eligible to be a member of another pension fund or retirement system established under any law of this State, such person shall not be enrolled in such other pension fund or retirement system if he is eligible to receive such pension or retirement allowance.
N.J.S. § 43:3C-1