The gun rights activist who waged a very public legal war over the right to freely distribute 3D-printed gun schematics over the internet is facing serious charges that have nothing to do with firearms.

According to a law enforcement press conference today, Cody Wilson, 30, is believed to have traveled to Taipei after learning that he was under investigation for sexually assaulting a 16-year-old. Wilson, who travels frequently, also missed his scheduled return flight.

According to an affidavit filed on Wednesday, Wilson is charged with the sexual assault of a 16-year-old girl in Travis County, Texas. The affidavit describes how Wilson, an Austin resident, began communicating with the alleged victim under the handle “Sanjuro” using the website “SugarDaddyMeet.com.”

The two continued talking via iMessage and Wilson allegedly identified himself to the victim and mentioned that he was a “big deal,” prompting her to find his name featured in recent news stories. In addition to his high-profile role in the debate over 3D-printed firearms, Wilson also attracted attention when he founded Hatreon, a crowdfunding site for fundraisers that violated the rules of sites like Patreon and Kickstarter.

The affidavit, published in full on Ars Technica, details how the two met in person on August 15 at a local coffee shop and Wilson then took the victim to a hotel in a vehicle registered to his company, Defense Distributed. The victim alleges that the sexual assault took place at Austin’s Archer hotel, after which Wilson paid her $500. Surveillance footage corroborates the victim’s story.

Austin’s police department is coordinating with international authorities to bring him back to the country to face the second-degree felony charges, which could be punishable by up to 20 years in prison.

Update: A reporter with the Austin American-Statesman reports that the U.S. Marshals have issued a wanted poster for Wilson.