Chinese spies in U.S. hunting for man who could be the 'most significant defector in decades' are warned off by White House US warned Beijing about covert Chinese agents operating in America to pressure fugitives such as defector Ling Wancheng to return to China Operation Fox Hunt part of large effort by Beijing to repatriate fugitives China’s former president, Hu Jintao, employed Ling’s brother as an aide Brother in July accused of bribe-taking and illegally obtaining state secrets Ling may have got sensitive information about Chinese leaders from him Chinese President Xi Jinping will make his first state visit to...