SGB: "...the possibility that you've been set up with a false story so people can have conculsive proof..." This could very well be the foundation of what is going on here. I do believe that the "at work" element here is pivotal.
Just curious, WouldYouTell, does anyone else at work know about it? If they aren't talking, isn't that a clue to you that this is out of bounds? No one likes a tattle tale and consequences to whistle blowers are generally not fairytales.
As an aside, my sister was "set up" at her place of employment. Her self-absorbed (edit other adjectives) nature can be irritating. Someone (a senior man in her dept) told her that if a sibling was pregnant (moi at age 45, married, third child) and their parents were deceased (they are), that the employee could take maternity leave to assist the sibling.
Without asking me, she informed me that she put in the paperwork to HR to do this. I was too shocked to say anything and relied on HR to turn her down...and they did. She was so sure of her entitlement that she insisted they reprocess the paperwork a second time. There she was, applying for maternity leave even though she was not pregnant. She fell for it hook, line and sinker, didn't she?
The unintended consequence for her was that it was the point of "enough is enough" for me in my relationship with her and her incessant campaign to diminish me. (That is probably why she was so oblivious to the dynamic at work.) I have not seen her in 5 years, such a relief.