A British political activist has been refused entry into Hong Kong after receiving threats from China.

Benedict Rogers, the deputy chair of the Conservative Party Human Rights Commission, was stopped at immigration and denied entry into the former British colony on Wednesday morning, according to the Guardian.

Rogers told the newspaper: “It is absolutely bizarre… I feel shocked. I had received a warning that this might happen, so I was mentally prepared for it but was hoping it wouldn’t happen.”

“They [immigration officers] gave me no explanation at all.”

According to the Hong Kong Cultural & Political Forum, a network for expat Hong Kongers, the Chinese embassy in the UK warned Rogers not to visit the city to meet political figures unsavoury to the Chinese regime.

The embassy sent him a message on Tuesday saying: "I am afraid that if he [Rogers] insists on travelling, he will not be able to enter," the group claimed.

British nationals can legally enter Hong Kong without a visa for up to six months.

Rogers lived in Hong Kong between 1997 and 2002, shortly after Hong Kong was returned from British to Chinese control.

He has since spoken out against China's encroachment on Hong Kong's political freedom, and has called on international leaders to "stop the shameful kowtowing" to the "thuggish regime in Beijing."

"I did see some early warning signs of the erosion of freedom [when he lived in Hong Kong], but they were more through self-censorship than by the Communist Party's direct interference," Rogers wrote in a blog post for the ConservativeHome website in June.

"The erosion has accelerated in the past four years," he continued, referring to recent events including the city's disqualification of pro-democracy lawmakers from its parliament and disappearance of five booksellers who sold politically sensitive publications in the city.

"Beijing is looking for any excuse to deny the pro-democracy movement any space," Rogers added.

Hong Kong and China operate by the "One Country, Two Systems" principle, which allows certain Chinese regions to retain distinct economic, political, and legal systems, while remaining under Chinese sovereignty.

Rogers told the Guardian: "I said [to the immigration officer who escorted him to his flight out of Hong Kong]: 'Does this mean one country, two systems is dead? Is it one country one system now?'