A lawyer for Raymond Merril Jessop asked the 3rd Court of Appeals in Austin on Wednesday to overturn his conviction and 10-year sentence.
Jessop was the first member of the Fundamentalist Church of Jesus Christ of Latter Day Saints to be tried after a 2008 raid at the group's Yearning for Zion ranch in West Texas.
Jessop was convicted in 2009 of sexually assaulting a 16-year-old girl who gave birth to his daughter.
The Austin American-Statesman reports that Jessop's attorney, Clinton Broden, argued prosecutors never proved the sexual encounter happened in Texas.
Attorney for the state, Ed Marshall, said jurors heard enough evidence to convict Jessop.
Information from: Austin American-Statesman, http://www.statesman.com