Tex. Prop. Code § 71.104
Any person, whether named in the escheat petition or not, who claims an interest in property that is the subject of an escheat proceeding may appear, enter a pleading, and oppose the facts stated in the petition.
Acts 1983, 68th Leg., p. 3588, ch. 576, Sec. 1, eff. Jan. 1, 1984.