N.J. Stat. § 53:1-9.3

No such person who, at the time of the granting of his said leave of absence, is a member, in good standing, of any pension retirement or annuity fund, shall suffer the loss or impairment of any of the rights, benefits or privileges accorded by the laws governing such retirement pension or annuity funds; provided, however, that in the event of the death or disability of such person while on such leave of absence, the pension to be paid such person or his dependents shall be the amount, if any, remaining after calculating the amount of pension that would be paid if such person had continued in active service in the State Police, until the time of his death or disability, and had continued to receive the same compensation as he received at the time of his entry into such special duty, and deducting therefrom the amount of any pension received from the Government of the United States. During the period beginning with the time of the commencement of any such person's leave of absence and ending at the time of such person's return to active service, the State shall contribute, or cause to be contributed, to the said pension retirement or annuity fund, the amount required by the terms of the statute governing such fund, amount to be paid by the State based upon the amount of compensation received by such person immediately prior to his entry into such special duty in the said Federal Bureau of Investigation, and any such person, during his said leave of absence, shall be required to contribute the amount required by statute to be paid by members of such fund, based upon the amount of compensation received by such person immediately prior to his entry into such special duty in the said Federal Bureau of Investigation. L.1951, c. 117, p. 526, s. 3.