China warned the UK not to meddle in its affairs over Hong Kong on Wednesday after the arrest of a British Consulate official worsened already strained ties between Beijing and London.

Simon Cheng, 28, a trade and investment officer at the Hong Kong consulate’s Scottish Development International section, went missing on August 8 on the way back from a business event in the Chinese city of Shenzhen. Britain has said it is “extremely” concerned.

News of his disappearance became public on Tuesday, prompting China on Wednesday to confirm that it was holding him on allegations of violating local law, without revealing any further details.

Geng Shuang, the Chinese foreign ministry spokesman, said the case was linked to China’s Public Security Administration Punishment Law, a statute pertaining to minor violations. Individuals can be held under administrative detention for as long as 15 days, which would be roughly until Friday.

Mr Geng warned the UK to back away from the affairs of its former colony. “The British side has made a lot of erroneous remarks on Hong Kong,” Mr Geng said, urging London “to stop pointing fingers and making accusations.”

"He is not a British citizen. He is a Chinese person, so this is entirely a matter of China’s internal affairs," Mr Geng said of Mr Cheng.