China on Thursday accused the UK of sheltering "wanted criminals" after prominent Hong Kong pro-democracy activist Nathan Law said he had been granted political asylum there.

London and Beijing are at bitter odds over the fate of Hong Kong, with Britain accusing China of tearing up its promise to maintain key liberties in the former colonial territory for 50 years after the handover.

Law said on Wednesday he had been granted asylum in Britain, after fleeing the semi-autonomous territory following the introduction of sweeping Chinese security laws.

"The UK is clearly a platform for Hong Kong independence agitators, and provides so-called shelter for wanted criminals," foreign ministry spokesman Zhao Lijian told reporters.

Describing Law as a "criminal suspect," Zhao called the move "gross interference" in Hong Kong's judiciary.

"The UK should immediately correct its mistake, and stop interfering in Hong Kong affairs and China’s internal affairs," he added.

Law, a  27-year-old former Hong Kong lawmaker and student activist, fled to the UK in July 2020 in the weeks after the National Security Law, opposed by pro-democracy protesters, was imposed.

Law wrote on Twitter that he had been granted asylum in the UK after several interviews over a period of four months.

"The fact that I am wanted under the National Security Law shows that I am exposed to severe political persecution and am unlikely to return to Hong Kong without risk," he wrote.

The activist highlighted the plight of other asylum seekers in the UK from Hong Kong who might not have the same weight of evidence behind their claims.

"I hope that my case can help the Home Office understand more about the complicated situation in Hong Kong.

"To free more protesters from Beijing’s authoritarian oppression, the Home Office could consider more comprehensive evidence," he added.

Champion of democracy

Law's fate and the fate of potentially millions of Hong Kongers who Britain has offered a route to escape China's crackdown, has become a point of bitter diplomatic contention between Beijing and London, which ceded the former colonial territory in 1997.

China said earlier this year it will not recognise the British National (Overseas) passport for Hong Kongers because of a new visa scheme introduced in January offering a pathway to full UK citizenship for those who want to leave the territory.

Beijing and London have in recent weeks also disagreed over Chinese sanctions against four UK entities and nine individuals including lawmakers that have spoken out in defence of China's Uyghur Muslim minority.

Last year, Britain protested at jail terms handed to three leading activists from the pro-democracy party Demosisto, which Law cofounded.

The party disbanded on the same day China's new security legislation was imposed in Hong Kong.

In exile, Law has continued to champion the cause of pro-democracy groups in Hong Kong on social media.

Last month, he hit out at mass trials of activists in Hong Kong saying that they showed that "the Chinese Communist party nakedly abuses its powers and uses the courts to demonstrate that power".