Executives and engineers at some of Japan's largest hi-tech companies have been ensnared in a "honey trap" set by Chinese women working at a Kyoto hostess bar, according to a report in a Japanese news magazine.
Officials and employees of at least five leading companies were patrons of the club, in the city's Higashiyama ward, before the club shut down in June and the Chinese manager disappeared, according to Shukan Jitsuwa.
The bar, which was not named, charged an entry fee of 20,000 yen (HK$1,600) and employed eight hostesses who were reportedly skilled in pouring drinks and flattering egos.
The manager denied to authorities that customers spoke about their work at the club, but admitted that the women were available to meet the men at later dates.
It was reported that the women would then encourage the men to discuss the new technologies that were being developed at their companies and corporate strategies for operating in the Chinese market. Even if that did not work, the magazine suggested, the men would have been highly susceptible to blackmail.
Before she disappeared, the Chinese manager was initially questioned by police looking into fake marriages, including one in which a 32-year-old Chinese hostess married a 52-year-old member of Japan's Self-Defence Forces.
The officer was a regular at the club, but was dismissed from the service when the case came to light. He has been charged in connection with the marriage. The magazine said the marriage was part of a Chinese effort to obtain information on Japan's submarine fleet.
"Engineers who encounter Chinese girls at sex parties ... are coerced into leaking information," a source told the magazine.
"There are also cases where engineers are in debt to loan sharks. They will be threatened into providing information.
"China is trying to get submarine technology from Japan through their intelligence services, so they have stepped up their collection efforts."
Allegations that China is becoming more aggressive in its espionage activities, in tandem with its territorial claims in the South China Sea, have been supported by a number of similar cases.
In May 2012, the Chinese embassy in Tokyo was forced to deny investigators' allegations that a former diplomat was a spy involved in illegal commercial activities.
The embassy's former first secretary was named as Li Chunguang and was reportedly from a PLA intelligence unit.
Li, 45, returned to Beijing shortly before Japanese authorities filed a request with the embassy that he turn himself in for questioning.
Tokyo police had been monitoring Li's movements for some time, while a company in Tokyo paid an "advisory fee" of 100,000 yen into his account every month. The company apparently had plans to expand its business into the Chinese market.
Two months previously, a Chinese employee of Yamazaki Mazak copied data from the machine tool manufacturer's records. And in 2007, police in Nagoya arrested a Chinese national working for car parts manufacturer Denso for allegedly downloading some 130,000 designs from the company's database.
Shukan Jitsuwa said that after the police opened their investigation into the Kyoto hostess bar, the women quickly left and may had moved to similar establishments in other parts of Japan to continue their work.