U.S. Auto Engineer in Chinese Custody for Over a Year SHANGHAI - An American automotive engineer has been detained by the Chinese police for over a year on charges of violating trade secrets, according to U.S. officials. Hu Zhicheng, a Chinese-born American citizen who won awards in the United States for his work developing catalysts that control auto emissions, is being held because of a dispute with a former business partner in the northern port city of Tianjin. The U.S. Embassy in Beijing says that his wife, also a Chinese-born American citizen, is also a suspect in the case. She is now living in the United States with the couple's children. Mr. Hu's detention is the latest trade secrets case to shed light on China's harsh legal system and the complexities that can emerge in this country's dynamic but ruthless business system. Earlier this year, Stern Hu, a Chinese-born executive working for Rio Tinto, the Australian mining giant, was detained for stealing state secrets while negotiating with some of China's biggest steel producers. Because Mr. Hu is an Australian citizen, that case created diplomatic tensions between China and Australia, and it still has not been resolved. In American engineer's case, U.S. officials say they have been allowed to visit Hu Zhicheng nine times but that the mail he receives is being censored and that he is not allowed to receive any written communication from his wife. U.S. officials declined to discuss details of the case but said that it was still being investigated. Mr. Hu's lawyer could not be reached for comment. A spokeswoman for the Tianjin police, who only gave her name as Ms. Liu, said by telephone Thursday that it was inappropriate to discuss the case. "It involves business secrets," she said. It'd be too complicated to disclose any details. We're not sure when the case will be closed. Mr. Hu once worked in New Jersey for Engelhard Corp., which in 2006 was acquired by BASF, the German chemical giant. The Associated Press first reported Mr. Hu's detention on Thursday. U.S. officials said he was initially arrested in November 2008, but formally arrested and charged in January 2009, while working for a company called Hysci Specialty Materials. Chen Xiaoduan contributed research.