N.J. Stat. § 40:48-6
When any municipality maintains a municipal building, or rooms or space for the use and purposes of the municipal government, owned or leased by it, or occupied by virtue of any other permission or authority, all books, records, data, accounts, maps, and papers relating to the government or the conduct of municipal business and matters shall be kept therein, in the custody of the governing body. The governing body shall provide therein a substantial safe or vault, reasonably secure against fire and ordinary theft, for the safe-keeping of such books of account and valuable records and documents, papers and other data. The governing body may designate some other place or places for the safe-keeping of such books, valuable records, documents and papers affording equal or greater security against fire and theft.
N.J.S. § 40:48-6