Some time ago, I was captivated with a lurid anecdote concerning the
discovery of the skeletons of infants or fetuses within the walls of
old  monasteries and churches.  Supposedly, nuns who were impregnated
by priests would either dispose of their pregnancies or newborns and
then hide the evidence by placing the remains within the walls of the
church. Furthermore, the anecdote suggested that while this wasn't
commonplace, nor was it an isolated incident.

I have yet to be able to confirm this story, and I am wondering
whether anyone can point me to a reputable source that can do so.  Did
these events actually occur, or were they just a hoax or
misinformation?

Well, I can tell you that anti-Catholic propoganda books of the 19th
century (of which I have several in my collection) frequently told
this tale--along with a host of other tales that had no evidence to
back them up. The fact that this story was included in such books is
enough to make me suspect it as false...

Kristina

This seems pretty unlikely.  If you've ever had a mouse die in your
wall, you'll know that this is not a very good way to hide a body.