The affidavit filed Wednesday in state district court in Austin accuses 30-year-old Cody R. Wilson of sexual assault of a juvenile. It says he met his alleged victim through the website SugarDaddyMeet.com.
Wilson hasn't responded to a phone message. Jail records indicate he's not in custody.
Wilson is identified in the affidavit as the owner of Austin-based Defense Distributed. He announced last month that he is selling 3D-printed gun blueprints through his website after a federal court blocked posting them online for free.
That followed a collection of states suing to stop a settlement that the federal government had reached with Defense Distributed.
RELATED: 3D-printed guns: Everything to know about the yearslong legal battle over downloadable blueprints