There has been five cases similar to this, recently, I think this has reached the news because of the multiple child deaths.
SS involvement can give abusive Parents power against relatives that are trying to help the children.
Then if services are dismissing the information being given, then there is little that you can do.
Baby P's Dad was arrested and an injunction obtained against him, because he wanted to take his son out if the abuse.
I think that as the bedroom tax forces non resident parents parents into house shares and hostels, because they cannot rent their own property, we will see an increase in child abuse cases that could of been prevented, by the other parent, or relatives, having overnight stays etc.