How could my enemies find my victims’ corpses left in a Magnificient Mansion?

The magnificent mansion spell states:

When the spell ends, any creatures inside the extradimensional space are expelled into the open spaces nearest to the entrance.

Based on these two questions, it was determined that corpses are objects and that objects could be ‘given’ to the mansion (though I’m not sure I’m satisfied with that conclusion):

  • Is a dead creature's body considered an "object"?
  • What happens to items left in Mordenkainen's Magnificent Mansion?

Regardless, if we take that conclusion as given, suppose I provided the servants poison for the entire banquet and had them use it to massacre a 100-person dinner party. When others attempt to find the deceased using divination magic, what sort of reading would they get? Assuming they could figure out where the bodies were, how could they go about recovering them?