Polygamist Leader Warren Jeffs says he never married his underage daughter to an adult, but officials say they have found evidence to the contrary.
Photos, diaries, and a marriage record all suggest that Jeffs' daughter who was 15 at the time, married a 34-year-old man.
The documents were filed in a report by the girl's guardian and given to a San Angelo court.
Members of the FLDS sect said in past interviews that no marriage had existed.
Jeffs' daughter, who is 16 and now in her mother's care, was one of the children who was taken from the Sects' ranch near Eldorado.
She is scheduled to appear before a grand jury next week as part of the sexual abuse case.