China on Monday accused Britain's Secret Intelligence Service (MI6) of recruiting a couple who worked for the central government to spy for the UK, adding to months of mutual espionage allegations between Beijing and Western powers.

The Ministry of State Security said in a post on its official WeChat that MI6 operatives convinced a man surnamed Wang, who worked in a "core confidential role" in the central state apparatus, to defect along with his wife, surnamed Zhou.

"Recently, after careful investigation, the national security organs uncovered a major espionage case in which the British Secret Intelligence Service (MI6) instigated a couple, Wang and Zhou, who were staff members of a central state agency of China, to defect," it said.

The ministry said British spies began cultivating Wang after he began a course of study in the UK in 2015, arranging dinners and tours for him in order to "understand his character weaknesses, interests and demands".

After learning that Wang "had a strong desire for money", they then approached him to provide well-paid consulting services that came to involve the internal workings of central state agencies, the ministry said.

MI6 personnel later revealed their identities to Wang and directed him to return to China to collect intelligence, convincing him to coerce Zhou into doing the same.

The ministry said it had gathered evidence and taken "decisive measures" against Wang, adding that the case was under further investigation.

The statement gave no details of Wang or Zhou's current occupations in China, the nature of the information they provided, or their whereabouts.

AFP has contacted Britain's Foreign, Commonwealth and Development Office, which handles MI6 press enquiries, for comment.

China and Western powers have long traded accusations of spying but only recently started to disclose details of alleged individual cases.

Last month, British police said Matthew Trickett, who had been charged with helping the semi-autonomous Chinese city of Hong Kong to gather intelligence in the UK, had been found dead in unexplained circumstances.

And in April, German authorities arrested four people on suspicion of spying for China, in the same week that British police charged two men with passing sensitive information to Beijing between 2021 and last year.