The British government said on Tuesday it had not been granted access to a Hong Kong bookseller and British passport holder who disappeared last year.
In a television interview with China's Phoenix Television late on Monday, Lee Bo, a dual British and Hong Kong citizen, said he had returned to China voluntarily and would renounce his British citizenship.
Lee and four associates went missing over the past half year, sparking fears that Chinese authorities had abducted some of the men and taken them back to China.
"Despite formal requests, we have not been granted consular access to Mr Lee," a British government spokesman said in a statement.
Lee, 65, was the publisher of Mighty Current Media, a Hong Kong–based publishing house popular among mainland tourists for its scandalous books about the private lives of Chinese politicians. Lee disappeared from his warehouse in late December, turning up in mainland China one week later saying he was “assisting an investigation,” prompting speculation that he had been abducted by Chinese agents.
The case drew international concern over fears Beijing was eroding the "one country, two systems" principle that allows Hong Kong to maintain civil liberties such as freedom of the press and a high degree of control over its own affairs.
Lee's case in particular rang alarm bells because of suspicions he was snatched by mainland Chinese security agents who crossed into Hong Kong.
Britain's foreign office said in a report in February that Lee, a British citizen, was "involuntarily removed" to the mainland. However, Lee said the claims were false and were being used by unnamed groups to hype up his case.
"After the Mighty Current affair emerged, I wanted to secretly go back to the mainland as soon as possible to resolve the company's affairs, then secretly return to Hong Kong," Lee said.
He added that he didn't want anyone to know and didn't want to leave any record of his journey at immigration checkpoints so he chose to use "illegal immigration," but did not give further details.
Lee also said he planned to renounce his British right of abode, or residency rights, though it's not clear why he used that term rather than citizenship.