China has detained a foreign national, Huang, who was the head of an overseas consulting firm, for allegedly spying on behalf of the United Kingdom. China’s Ministry of State Security (MSS) said Huang worked with Britain’s MI6 while leading a foreign consultancy.

The agency did not mention Huang’s full name, gender, or nationality, nor the company they worked at. Huang started working with MI6 in 2015 on intelligence matters, with the British agency directing him to travel to China multiple times to collect intelligence and identify potential assets. MI6 provided Huang with training and professional spying equipment for the exchange of intelligence and communications.

The British Embassy in Beijing has referred a case to the UK Foreign, Commonwealth and Development Office (FCDO), but the FCDO did not respond. China has been cracking down on international consulting firms, including Capvision, an advisory network with offices in Shanghai and New York.

The measures were part of Beijing’s wider efforts to increase oversight of sensitive information pertaining to national security. Capvision announced in October that it had successfully completed a national security inspection overseen by the Chinese government and come up with new compliance measures to address concerns.

The National Security Service (MSS) has launched a WeChat account to engage with the public and urge all members of society to join its fight against foreign spies. This move comes after the passage of a counter-espionage law in July, raising concerns among businesses about potential legal risks associated with the expanded scope.