The family of a British Consulate official in Hong Kong have rejected a "made-up" report by Chinese state media that he was detained in the mainland for visiting prostitutes.

Simon Cheng, 28, who works as a trade and investment officer at the Hong Kong consulate’s Scottish Development International section, disappeared on August 8 on the way back from a business event in the Chinese city of Shenzhen, which borders the financial hub.

His Taiwanese girlfriend was the last to hear from him when he messaged her from the Express Rail link in the evening on his way back to Hong Kong to say: “Passing through. Pray for me.”

After the UK expressed “extreme concern” about the case this week, China's foreign ministry finally broke its silence on Wednesday, confirming that he had been detained in Shenzhen but not releasing any further details.

The idea that Mr Cheng would have gone to a prostitute was met with widespread derision on Hong Kong’s social media channels, with some pointing out that he had only been on a day trip on official business.

A Facebook page run by Cheng's family dismissed the report. "This is a made-up crime of soliciting prostitution, everyone should see it's a joke," the comment said.