China's Ministry of State Security says it has found that a senior official of an overseas consulting firm was spying in the country in cooperation with Britain's intelligence service MI6.

The ministry said on Monday that the foreign consultant was trained by MI6, collected secrets and other intelligence in China and sent them to the British side.

The ministry did not mention the consultant's gender or nationality, the name of the consulting agency, or what secrets were stolen.

Last week, the ministry posted a video purportedly showing espionage activities by a person posing as an employee of a foreign consulting firm. The video also alerted viewers to the possibility of foreign spies approaching them in daily life. It urged the public to report suspected spy activities to authorities.

Chinese President Xi Jinping has been placing a high priority on national security.

Last May, media reported that Chinese security authorities investigated a consulting firm based in both the United States and China.