Actually, I have been in this situation as well. Athos is correct and it would be the agency that would have to pursue the person initiating false claims. I spoke to DSS legal department after a false allegation and investigation was completed (favorable report for me, I might add) and they stated they would not pursue based off a single false allegation, no matter how obvious it was, but if it were to happen again they would consider pursual. In my case, the investigator that investigated me and completed the report stated she would be following up with “the person” and notifying them of the seriousness of the false allegation and the potentional for legal recourse if it were to happen again.
Seems to me that we should be able to pursue something on our own for harassment or something like it, though. I’m sure you are probably in the same situation where false allegations are not the extent of what is going on at the moment.