Chinese authorities have detained a Japanese man in Beijing following media reports that a university professor was being held on suspicion of spying.

“The Japanese embassy in China confirmed that a Japanese man in his 40s was detained by Chinese authorities in Beijing in September for allegedly violating Chinese laws,” Japan’s top government spokesman, Yoshihide Suga, told reporters.

He did not specify the charges against the man, but Japanese media have identified him as a professor from Hokkaido University who was held on suspicion of spying.

The man, who has not been named, worked previously for the National Institute for Defense Studies in the defence ministry and the Japanese foreign ministry, according to local media reports.

In Beijing, China’s foreign ministry spokeswoman, Hua Chunying, said she did not know the details of the case but that China “has always handled foreign nationals suspected of breaking China’s law, in accordance with the law.”

China will “provide the necessary assistance in order for the Japanese side to perform the normal consular duties, in accordance with the relevant provisions,” Hua said at a regular press briefing.

She said the detention was a “one-off case”. “We hope that the Japanese side can remind its citizens to respect China’s laws and regulations, and avoid engaging in illegal activities in China.”

But, she added, China was “willing to work together with Japan to promote the continued progress of China-Japan relations along the correct path” and that “these are two completely separate issues”.

She noted that China’s vice-president, Wang Qishan, was scheduled to attend the enthronement of Japan’s Emperor Naruhito on Tuesday.

China has faced accusations, including from the Canadian prime minister, Justin Trudeau, of using detentions of foreigners as a political tool – and observers have called it “hostage diplomacy”.

Canada-China ties have soured since its arrest of Huawei’s chief financial officer, Meng Wanzhou, on a US warrant last December. Nine days later, Beijing detained two Canadians and accused them months later of espionage-related activities.

The two Canadians are among a string of foreign nationals arrested in China and charged with espionage or attempting to steal state secrets.

Australian academic Yang Jun, who also goes by his pen name Yang Hengjun, was detained in January shortly after making a rare return to China from the US. Beijing said in September that he had been formally arrested on suspicion of spying.

Since 2015, at least 13 Japanese citizens – all civilians – have been detained in China on various charges including espionage, Japan’s Kyodo News and the Asahi Shimbun reported.

Tokyo’s ties with Beijing have been at times strained by rows over history and territorial disputes but have been improving recently, with the Chinese president, Xi Jinping, expected to visit Japan early next year.