Death from natural causes (such as old age?)
Or are we talking bugs ie roaches, & mice meeting shoe leather?
I undestand the need of people from some eastern cultures to not purchase a home in which a person actually died, but there is no way that tossing this question out to the brokerage community will yield you and answer. Your best bet is to visit the property with the listing agent who has direct access to the owner, and request that this concern be addressed by the owner. ...Oh wait.. this isn't even on the market! Send them a letter or knock on the door. Good luck.