After a Taiwan-born physicist recently pleaded guilty to passing classified information on nuclear weapons to China, a group of Chinese scientists launched an appeal to the US for his release. Scientists from the government-run Chinese Academy of Sciences said they were shocked to learn that Peter Lee had admitted to divulging sensitive information in trips to the country in 1985 and 1997. In a letter to the media they said the lectures Lee gave at the academy -- in which he allegedly divulged sensitive information -- dealt with previously published materials. Lee is an expert in laser technology who worked at Los Alamos National Laboratory in New Mexico. He faces up to 15 years in prison and up to $250,000 in fines. The case against Lee highlights the US' growing concern over China's access to sensitive information pertaining to nuclear technology through its connections with Chinese students and businessmen living abroad.