Several South Korean diplomats stationed in the Chinese city of Shanghai are under investigation for their relationships (sexual and otherwise) with a Chinese woman who acted as a fixer for diplomats seeking access to Chinese officials. The woman, only identified as Deng, was most useful in helping obtain visas for North Korean refugees seeking to get to South Korea. Such "fixers" are common in China, and most foreigners are very dependent on them. The Chinese government wants it that way.
That can be seen from the fact that Deng was caught, by the South Koreans, with classified South Korean documents. She apparently got them from one of the South Korean diplomats at the Shanghai consulate. Deng was also believed to have had sexual affairs with several South Korean diplomats. At one point, she was apparently screwing two of them, without either of the South Koreans knowing the Deng was playing both of them.
China is widely known to use sex to obtain secrets from foreigners, inside and outside of China. Four years ago, Japan uncovered a widespread Chinese effort to use sex to steal military technology. Attractive Chinese female intelligence agents in Japan were marrying members of the Japanese armed forces, and then using that access to obtain military secrets. The situation was complicated by the military attempts to keep these "embarrassing incidents" secret. The government was particularly anxious to keep the Americans in the dark about all this, since the Chinese apparently got their hands on Aegis anti-aircraft system technology via their sexy spies.
Actually, most of the Chinese agents don't have to marry Japanese troops. Just putting out usually does the trick. In Japan, the military doesn't get much respect, and many of the bases are in backwaters. So the troops are pretty lonely. It's not unusual for Chinese women to be in the country, as many come, legally or illegally, looking for jobs. The set-up is perfect for using the old "honey pot" (sexual entrapment) routine to extract military secrets.
The military geeks are the most sought after, as these guys have access to the most valuable military secrets. Geeks tend to be least experienced with women, and most vulnerable to a clever, and shapely, Chinese spy. Military commanders are not sure if they have the problem under control, but now that the situation is out in the open, there will be more efforts to tighten up security. As the Japanese expected, the Americans were not amused. And the Chinese honey pot scandal was apparently one reason for refusing to sell F-22s to Japan. To make matters worse, part of the Japanese cover-up involved prosecuting the Chinese spies on immigration, not espionage, charges.
Using sex in intelligence work is nothing new, but the Chinese are probably the most enthusiastic, and successful, users of this technique these days.