A Texas man at the center of a legal battle over his plan to make instructions available for 3D printed plastic guns flew to Taiwan after learning police in Austin were investigating an accusation he had sex with an underage girl, police said on Wednesday.

Cody Wilson, 30, was placed under investigation after a counselor on Aug. 22 told police that a 16-year-old girl had said she was paid $500 to have sex with Wilson at an Austin hotel, Austin Police Commander Troy Officer said at a news conference.

Police later interviewed the girl and on Wednesday obtained a warrant for Wilson's arrest, but by then he had caught a flight to Taiwan, Officer said.