Estate Law Questions? Ask an Estate Lawyer.
In general - no, this does not seem appropriate or make sense. Theoretically it would be possible, but again, very unlikely.
If someone is trying to keep your right to an inheritance (trust, probate, or will) from you, I would recommend that you retain a probate attorney (a civil litigation attorney that specializes in these kinds of claims) to represent you in this matter. You may be able to reach a resolution without having to file a lawsuit, but it appears that you are being bullied and you need professional assistance to help level the negotiating field and better assert your rights.
You can find local attorneys using the State and local Bar Association directories, or private directories such as www.AVVO.com; www.FindLaw.com; or www.Martindale.com (I personally find www.AVVO.com to be the most user friendly).