N.J. Stat. § 19:58-30
The county board of elections shall keep, for a period of one year, all of the affidavits of residence and applications for Presidential ballots, together with all certificates accompanying the same, all voted Presidential ballots, and all of the certificates which have been detached or separated by said board from said inner envelopes, and all inner envelopes together with their certificates, and together with their contents, which have not been opened because the county board or the Superior Court rejected them. Specific power is hereby granted to the superintendent of elections in counties having a superintendent of elections and the prosecutor in all other counties to impound all such ballots whenever he shall deem such action to be necessary.
N.J.S. § 19:58-30