Adjective : a holeproof document.    From Dictionary.com. 

He is being measured for a complete outfit of holeproof clothing, and his motor will be a Ford of seventeen thicknesses, with armoured steel windows, and fitted with first-aid accessories, including liniment, restoratives and raw steak.    From Wordnik.com.  [Punch, or the London Charivari, Volume 159, July 7th, 1920] Reference

"Oh, well, it surely seemed a shame, but no one really was to blame; and this year all the birds around (I heard it from a wren) will put their mail most carefully safe in a holeproof hollow tree.    From Wordnik.com.  [Zodiac Town The Rhymes of Amos and Ann] Reference