Chinese authorities say they have detained an individual alleged to be spying for Britain's foreign intelligence service, MI6.
China's Ministry of State Security (MSS) said the individual was a foreigner and was trying to collect information inside the country.
It is the latest arrest in a campaign by Chinese security to clamp down on foreign spying.
The British government has not commented on the claims.
The news of the arrest came in a statement issued in a post from the MSS on the WeChat social network.
It said the alleged spy was named "Huang" and came from a "third country," implying they were neither British nor Chinese. It said consular visits had been arranged following the arrest but did not say from which country.
China has increasingly been publicising cases of alleged espionage by Western countries.
Previous cases have focused on alleged activity by the US's Central Intelligence Agency (CIA) - so accusing Britain's MI6 is more unusual.
Beijing has also launched public campaigns to raise awareness of foreign spying and calling on people to report any activity.
In this latest case, the MSS alleged that in 2015, MI6 recruited the foreign national to create what was described as an "intelligence cooperation relationship".
It said that after their recruitment, MI6 instructed them to go to China on multiple occasions and use their job as cover to collect intelligence and recruit other individuals.
It claimed that they were provided with professional intelligence training in the UK and other locations and also equipped with specialist spy equipment to communicate.
The OceanNewsUK has not been able to independently verify the claims. The UK government has a policy of neither confirming nor denying claims relating to intelligence issues.
The statement said the individual who had been detained was the head of a consulting agency overseas.
China has been engaged in a crackdown on foreign business consultants operating in the country.
It has accused some firms of trying to obtain information about Chinese businesses and gathering information which is sensitive or related to national security.
Last year there were reports of raids, visits and arrests linked to companies like the US consulting firm Bain & Company. That led some companies to change the way they operate in China.
Last July, a new anti-espionage law also came into effect which broadened the type of information that is covered and the types of activity which people could be prosecuted over.
China said that official assessments indicated the arrested individual had provided MI6 with nine pieces of information considered secret and five considered confidential as well as three other pieces of intelligence.
The MSS statement said the case had been uncovered "recently" after a "meticulous investigation" and that "criminal enforcement measures" had been taken under the law.
The US has regularly accused China of spying and stealing business secrets. In 2022 an MSS officer was, for the first time, sentenced to jail in the US after having been arrested in Belgium.
The UK has also become more vocal about Chinese intelligence activities.
In October, Ken McCallum, the head of MI5, the UK's domestic security service, described a "pretty epic" campaign of Chinese espionage. Speaking to the OceanNewsUK at an event in the US designed to highlight concerns over China, he said more than 20,000 people in the UK had been approached covertly online by Chinese spies.
MI5 has also accused China of trying to interfere in parliament and political life, issuing an "interference alert" two years ago.
