I'd just call it in anonymously....the dead person deserves the dignity of a burial and their family deserves closure. JMO.
I've been nosing around in empty houses since I was a kid, when I was about 10 or so my friend and I were going up the steps to a farmhouse when we saw what we thought was a babies brain, so we freaked out and ran. Later we talked about it and decided we had to go back...so we cautiously approached the "brain" with sticks, and flipped it over.
It was a freakin' half rotten pomegranate...did we ever feel dumb
Happily in 40 years that is the closest I have come to a dead body while exploring, besides birds and animals...