A British national was sentenced to five years in jail for spying in 2022, China's Ministry of Foreign Affairs (Mofa) has now revealed.
The defendant - named as Ian J Stones - committed the "crime of illegally obtaining intelligence for overseas actors", a Mofa spokesman said.
The spokesman added that he had appealed against the sentencing but the case was upheld last September.
This was only revealed in a Mofa briefing on Friday.
According to an article by the Wall Street Journal (WSJ), Stones worked in China for four decades with big US firms like General Motors and Pfizer and is believed to be aged around 70.
He set up a Beijing-based investment management consulting firm some 15 years ago, said the WSJ, citing corporate records, online profiles and people who know him.
Mofa spokesman Wang Wenbin said the court had "tried the case strictly in accordance with the law", adding that Beijing had "fully guaranteed the various legitimate rights" and arranged for British officials to visit him and attend his trial.
Stones' daughter told the WSJ that embassy officials and one family member were permitted to witness one hearing but not the actual trial, adding that none of them had been permitted to see any of the legal documents related to the case.
She also claimed her father was healthy at the beginning of his detention but had received "inconsistent medical care and poor nutrition leading to severe and life-threatening injuries".
Ms Stones said British Embassy staff have been able to visit Stones every four to six weeks to check on him, but that there have been long periods where they received no news and were not permitted any consular visits.
In a statement, Mr Wang added that Stones was accused of "being bribed into providing intelligence by external forces" .
"The judicial organs strictly promote the handling of cases in accordance with the law, safeguarding the rights and legitimate interests of both Chinese nationals and foreigners," he said.
This latest reveal comes as China increasingly publicises cases of alleged espionage by Western countries.
Beijing has also launched public campaigns to raise awareness of foreign spying and has been calling on people to report any suspicious activity.
Earlier this month, Chinese authorities said they had detained an individual alleged to be spying for Britain's foreign intelligence service, MI6. The OceanNewsUK was not able to independently verify these claims.
The UK government has a policy of neither confirming nor denying claims relating to intelligence issues.
