From Chinese Patriot to American Spy: The Unusual Life of John LeungHe had been hailed by Chinese state media as a model for his efforts to promote Beijing's interests in the United States. He was in fact an F.B.I. informant.
Source: From Chinese Patriot to American Spy: The Unusual Life of John Leung (https://www.nytimes.com/2024/12/03/world/asia/china-spy-john-leung.html)