Not sure what you mean by disappear. Do you mean magically go poof? Made invisible? Carried away by an unknown party? Decompose?
Is your novel based in the real world or a fantasy world? For a real world you have three options, carried off by someone, dragged off by animals or decomposed (I'm counting all kinds of destruction, bugs, acid, explosion etc...).
For fantasy your options are pretty much open. Magic, ghosts, aliens, zombies...
So to answer your question, in a real world scenario, bodies can be removed, in a fantasy world, then yes a body could disappear.