China is expected to decide soon whether to formally arrest a Japanese businessman detained in Beijing since March on suspicion of espionage, sources familiar with the bilateral relationship said Wednesday.

The Chinese government recently informed Tokyo that the Japanese national has been placed in criminal detention, which allows for up to 37 days of detention while authorities decide on formal arrest under Chinese law.

Beijing has not responded to Tokyo's repeated requests to quickly release the employee of drugmaker Astellas Pharma Inc.

His prolonged detention could further worsen Sino-Japanese ties already strained over the release of treated radioactive water from the crippled Fukushima nuclear power plant into the sea, which started in late August.

Staff at the Japanese Embassy in Beijing met the man on Sept. 13 and confirmed he had no health issues, the sources said. The embassy has been in contact with his family and supporting them.

A Japanese government official said Wednesday that the man's criminal detention is "unacceptable," and Tokyo will seek his release "as soon as possible."

Chinese Foreign Ministry spokeswoman Mao Ning said at a press conference Wednesday she is not aware of the Japanese citizen's situation, adding Beijing will treat his case in accordance with the law and "the lawful rights and interests of the person concerned will be protected."

The senior Astellas Pharma employee was detained in March, just before his scheduled return to Japan. The specific details of how he may have violated the counterespionage law and criminal code in China remain unknown.

In April, then Japanese Foreign Minister Yoshimasa Hayashi strongly demanded the man's early release in talks with Premier Li Qiang and other senior Chinese officials during a trip to Beijing.

In July, the Japanese embassy was granted in-person consular access to the businessman for the first time. Previously, the Chinese government had only allowed monthly consular access to him via video link, citing the need to prevent the spread of COVID-19.

On July 1, a revised counterespionage law took effect in China, broadening the scope of what constitutes spying activities.

Since the country's counterespionage law first came into force in November 2014, 17 Japanese citizens have been detained for alleged involvement in spying activities. Five of them are still being held, according to the Japanese government.

==Kyodo

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