With respect to LordSmacker, I'm not convinced it happened.
All-righty then, I've actually been round and interrogated the niece now and can clarify one or two things. I understand completely your scepticism, I was of the same mind when the story slipped out at a family gathering (and everyone quailed when my ears pricked up and demanded to know the detail which had been carefully concealed from me!).
Well, it seems that the mother of one of my niece's classmates had heard from someone else (another classmate) that a death curse had been put upon her daughter, and the girl was now in bed suffering from a nasty bout of flu. This woman, who happens to be a teacher at the school in question, is noted for being, um, "quirky" (aka BatShit Crazy), decided that sorcery was behind the illness and her daughter was DOOMED. Things were said in the staffroom and later on, the Head of Year pulled my niece up about it and asked if she knew anything about curses.
When she claimed to know nothing, the Head told her that an allegation had been made and asked her to write a statement refuting that she had any knowledge or belief in witchcraft, and that no "death curse" had been placed upon the other child. Failing that, she'd be excluded. My niece wrote all this out, and took a photo of the piece, which I've seen, but which is frustratingly out of focus. Certain people are working on it right now to see if it can be sharpened up.
Satisfied, the Head of Year deemed the matter closed.
Then her Dad found out. Now my Bro-in-Law isn't a jolly, happy-go-lucky fellow, but then he's not a shit-kicking hard man either. He's father to 3 teenage girls, so takes no crap from anyone. No likely lad is getting past him standing with folded arms on the doorstep, if he decides they are a wrong 'un.
Well, apparently he steamed straight up to the school and demanded the Head of Year put a stop to all that bollocks there and then. The HoY, a man with a nickname which suggests he is not to be trifled with, duly shat himself and agreed. I have yet to find out what happened to the signed statement, or what the official outcome is.
His next plan was to "speak" to the parents of the kid that made the original allegation, and her chums who backed her up about death curses being lobbed around. He was dissuaded, on the understanding that they stayed away from the niece, along with the crazy teacher.
So, less of a witch-hunt, and more of a HoY trying to placate a shrill teacher/parent, not expecting to be pulled up by an angry father - angry at the potential disruption to exams rather than being accused of being a witch, he doesn't believe in any of that nonsense. I actually feel for the poor guy at school, who would want to be in the middle of bickering teenage girls and an unstable mother?
Now, there is one more aspect to this tale, but it's one which I dare not divulge, in case it identifies anyone. Put it this way, if you are the kind of person who thinks the Amityville Horror is factual, you'd fucking LOVE it. It certainly made me gasp. I may be able to reveal more at some point in the future, but it's a little sensitive, I'm sorry.