Washington, June 1 - A senior Chinese official whose son-in-law has been detained in China for almost six months said he was shocked to learn of Qin Guanggang's arrest but hasn't tried to intervene on his behalf. Feng Yuanwei, a member of the powerful standing committee of the Chinese People's Political Consultative Conference and former vice secretary-general of the Sichuan Provincial Party Committee, told Radio Free Asia (RFA) he feared allegations of corruption if he tried to help his son-in-law. "I have never interfered on behalf of my relatives. On the mainland, the wind of corruption is prevalent. The masses deeply resent it. So we cannot use our power for our own relatives," Feng said, breaking his public silence on the case for the first time. "I was shocked to hear it. I couldn't believe it," Feng said in an interview to be broadcast in China on Friday and Saturday. "Of course I am concerned, but it's inconvenient for someone in my position to ask too many questions." "I am not sure what the charge is. It's probably disclosing state secrets," he said, adding: "Qin Guangguang would not do anything to betray the country. We wait quietly for the administrative departments to arrive at a conclusion... maybe it involves economic secrets." Feng described Qin - a member of the minority Zhuang people - as "smart and capable," well-liked by his in-laws. Qin graduated from China's Central Ethnic University and came to the United States in 1989. He was a visiting scholar at the University of Michigan, University of Chicago, and Stanford. He later went into business and in 1994 was hired as the Beijing representative of a U.S. pharmaceutical group. He disappeared in February 2000 and is currently held by the Ministry of State Security. In February this year, Hong Kong's Ming Pao newspaper Web site reported that Qin was to stand trial for divulging state secrets. Qin's wife, Feng Li, said she has received negligible information about her husband's case. "Concerned departments have spoken with me about his case, and they said they'd let me know when they have arrived at a conclusion," said Feng, editor in the Beijing bureau of Taiwan Echo (Han Sheng) magazine. "It's unbearable." "Economically and spiritually, I rely on friends to help me make it," she said. "I don't know why he's been detained. My hair has turned white trying figure out why... It's been almost half a year and there has been no news at all. I can't sleep at night." Along with Qin, Chinese authorities have detained four other Chinese-born Americans or U.S.-based Chinese academics in the past six months. Only one of them, U.S. permanent resident Gao Zhan, has been formally charged - a grave step in the Chinese legal process that usually precedes a conviction. The rationale for this string of detentions remains unclear, though some China analysts believe the arrests could be related to publication of The Tiananmen Papers. Radio Free Asia is a private, nonprofit corporation broadcasting news and information to those countries in Asia where full, accurate, and timely news reports are unavailable. Created by Congress in 1996, RFA aims to deliver such news reports - along with opinions and commentaries - and to provide a forum for a variety of voices and opinions. RFA currently broadcasts in Burmese, Cantonese, Khmer, Korean, Laotian, Mandarin, the Wu dialect, Vietnamese, Tibetan, and Uyghur. It adheres to the highest journalistic standards and aims to exemplify accuracy, balance, and fairness in its editorial content.