A worker at Britain's Hong Kong consulate has been detained for allegedly violating the law, the Chinese foreign ministry has said.

Simon Cheng Man-Kit has not been seen for 13 days after he failed to return to work after a business trip to Shenzhen in China earlier this month.

He has been given 15 days of administrative detention. Foreign ministry spokesman Geng Shuang offered no details about why he was being detained.

Less than 24 hours ago, Mr Shuang told reporters he was "not aware" of the case.

Speaking before Chinese authorities confirmed they are holding the 28-year-old, the UK Foreign Office said it is extremely concerned about his case and has reached out to authorities in the country.


Hong Kong: March of the umbrellas

Mr Cheng Man-Kit attended a business event in Shenzhen on 8 August, but did not return to Hong Kong despite being expected back the same day. His family reported him missing to police when he failed to return.

He was on his way back by train when he called his girlfriend, urging her to "pray for me", and told her he was approaching the border when he lost contact, according to news site HK01.

Mr Cheng Man-Kit is a trade and investment officer at the Scottish Development International section of the consulate.

Image: Simon Cheng Man-Kit failed to return to Hong Hong from Shenzhen earlier this month

Shenzhen, in southeastern China, links Hong Kong to the Chinese mainland.

His disappearance comes amid violent pro-democracy protests in Hong Kong which started almost three months ago.

Initially, the demonstrations were over plans for a law that would allow people in Hong Kong to be extradited to mainland China.

Image: Simon Cheng Man-Kit is a trade and investment officer in the UK's consulate in Hong Kong

But broader concerns about claims of police brutality and the erosion of freedoms under the "one country, two systems" formula - enacted after Britain handed Hong Kong back to China in 1997 - have now come to the fore.

The protesters want democratic reforms and the city's Beijing-backed leader, Carrie Lam, to resign.