Japan has urged China to release one of its citizens detained in Beijing as soon as possible and allow consular officials to meet with him, the top government spokesman said Monday, with China claiming he has been detained on suspicion of engaging in spying activities.

Chinese Foreign Ministry spokeswoman Mao Ning said the man is suspected of violating China's counterespionage law but did not elaborate on his charges. Japanese drug maker Astellas Pharma Inc. has confirmed he is one of its employees.

Chief Cabinet Secretary Hirokazu Matsuno told a news conference that the Japanese government is in contact with people related to the man, who is in his 50s.

Chief Cabinet Secretary Hirokazu Matsuno holds a press conference in Tokyo on March 27, 2023. (Kyodo)

Chinese authorities notified the Japanese Embassy in Beijing this month that they detained the man in the capital for what they said were violations of Chinese law, Matsuno said.

In Beijing, Mao also said in a press briefing Monday that Japan "needs to do more" to ask its citizens not to engage in such activities and better "educate" them on the issue as similar incidents have occurred in recent years.

A Japanese government source said China's counterespionage authorities detained the man. A diplomatic source familiar with Japan-China relations said the incident raises serious concerns as it could "deal an immeasurable blow" to bilateral ties.

Asked about international concerns over alleged ambiguity and arbitrary implementation of Chinese laws in espionage cases, Mao said, "Individuals engaged in unlawful practices should know what kind of illegal activities they have committed."

It is customary in China that allegations concerning national security are not released and trials are closed to the public. Even after rulings are finalized, the details are not announced in most cases.

The spokeswoman said China will handle the case of the Japanese businessman and make a decision on his release "in accordance with law" and facilitate consular access by the Japanese embassy to the citizen.

A source familiar with the matter has said the man was held by Chinese authorities just before his planned return to Japan this month.

Beijing has been beefing up its scrutiny of foreign organizations and individuals in the name of protecting national security, with a number of foreigners held after introducing a counterespionage law in 2014 and a national security law in 2015.

Since 2014, 17 Japanese nationals, including the Astellas employee, have been detained in China for alleged involvement in espionage activities. Five of them are still being held in China, according to the Japanese Foreign Ministry.

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