That's life. Just because it's unsubstantiated doesn't mean it should be hidden. Also, if it's so unsubstantiated, then sue them for libel.
We have all faced situations where people have accused us of behaving in a way or doing something we didn't do. When that has happened to me, I don't resort to trying to silence people. I just explain why they are full of sh1t.
If someone calls in a tip to the police saying you raped someone and you lost your job because of it you would be okay with that?