New Jersey Statutes Title 46. Property 46 § 6-3

Whenever any deed to or conveyance of real estate in this state shall purport to have been executed by virtue of any letter of attorney, and such deed or conveyance shall have been properly acknowledged and recorded, the recital of the letter of attorney in such deed or conveyance shall be prima facie proof of the existence thereof, notwithstanding the same may not be recorded, but only when such deed or conveyance shall have been recorded at least ten years, and the person claiming thereunder shall take and subscribe an oath that he has seen such letter of attorney so recited, which oath shall be recorded in the office of the county recording officer of the county wherein such real estate is situate, in the book therein provided for the recording of powers of attorney.