N.J. Stat. Ann. § 2A:67-7

Nothing in this chapter shall extend to discharge out of prison any person in custody by virtue of a judgment, order or process in any civil cause unless by virtue of the proceedings had for that purpose under authority of this chapter. A discharge, under this chapter, from imprisonment under a criminal charge shall not have the effect of discharging from prison a person imprisoned by virtue of any civil judgment, order or process but the person so discharged shall be kept in custody in such civil cause until discharged by proceedings had for that purpose.