Chinese military experts deny that China used secret US technology to develop its new stealth fighter, claiming the jet was a product of homegrown innovation, the Wall Street Journal reported. Speculation has risen as aviation experts noted that the J-20 stealth fighter prototype looked like a larger version of the US F-22 Raptor, which is currently the world’s only fully operational stealth fighter. The twin-engine J-20, which has drawn international attention because of its military advances, made its first public test flight two weeks ago during US Defense Secretary Robert Gates’ visit to China. "China is completely capable of making its own stealth fighter jet," said Li Daguang, a professor at the People’s Liberation Army’s National Defense University. "I think we developed the J-20 largely on our own research, but at the same time learning from existing foreign models."