I filed for divorce and now my (soon)husband is making false allegations against me, for the 4th time!?

It seems so obvious to me, and I don't understand why it is not obvious to you. "Detectives" don't take away your children. You should call the Department of Social and Rehabilitation Services in your area and find out if there's an open case against you - I'm willing to bet there isn't. It sounds like this is a set-up created by your ex-husband. That detective sounds like a phony. I would call the police if I were you.