Before you tell anyone "there is no record", list every place you looked. For each one, say whether you first searched it for something you knew was there. A search that could not find a known thing cannot find the missing one either, and its "nothing" sounds exactly like a real one.
This opens on a made-up example (a small office looking for a signed warranty). Change it, or press "Start empty". Everything stays in this browser.
The old laptop, the box in the basement, the inbox of the person who left, anything older than a search tool keeps. Writing these down is what makes the answer honest.
Real no: this search found something you knew was there, so its "nothing" for your item means something. Unproven no: you have not shown this search can say yes; its "nothing" might be a blind spot. Blind search: it missed a thing you know is there, so its "nothing" counts for nothing (common causes: a date limit, the wrong folder, a search that matches whole words only). Wrong place: the item could never have been here. Found: it is not missing.
This page does no searching and checks nothing on its own. It keeps your answers honest about their reach. A real no is still a no only for the places named.
One of the things the farm made at docatcdi.com. Free; it runs in your browser and sends nothing anywhere.