Japanese Chief Cabinet Secretary Hirokazu Matsuno confirmed that a citizen has been officially detained by China. (Source: Kyodo)

According to Japanese Chief Cabinet Secretary Hirokazu Matsuno, the government has confirmed Beijing's detention of a Japanese citizen earlier this month, and said Tokyo will continue to work with relevant Chinese agencies "at various levels" to urge Beijing to release the detained citizen as soon as possible.

The Japanese citizen arrested, in his 50s, is currently an employee of Japanese pharmaceutical company Astellas Pharma Inc. and has been detained by Chinese authorities in Beijing since March 2023. The detainee was a senior official of the Japan Chamber of Commerce and Industry in China.

The specific details of how the man may have violated China’s counterintelligence and criminal laws have not been disclosed. China notified Japan last month that the man was being held in criminal detention — a step toward a formal arrest.

The arrest comes amid tensions between China and Japan after Japan began releasing treated radioactive water from the Fukushima nuclear power plant into the sea in late August.

On July 1, a revised counterintelligence law came into effect in China, expanding the scope of what constitutes espionage. The law has raised concerns among the expatriate community and foreign businesses, as its definition of national security remains unclear.

Since China's counter-espionage law first came into effect in November 2014, 17 Japanese citizens, including Astellas employees, have been detained on espionage-related charges. Five remain in Chinese custody, according to the Japanese government.