HONG KONG (Reuters) - In a series of at least ten emails reviewed by Reuters, Hong Kong bookseller Lee Bo, specialising in gossipy publications about Chinese leaders, said he feared a missing colleague had been taken by agents from China for "political reasons".
Lee himself went missing in December, weeks after he sent the emails to the daughter of his colleague, Gui Minhai, who is still being held in China.
"We fear that he (Gui) was taken by special agents from China for political reasons," Lee said in one of the emails dated November 10.
Many people in free-wheeling Hong Kong and some foreign diplomats fear mainland agents illegally captured both Lee, a Hong Kong citizen and British passport holder, and Gui, a Swedish national.
The Hong Kong and Macau Affairs Office, an agency of China's State Council, did not respond to a request for comment. China has said its law enforcement officials would never do anything illegal, especially not overseas.
Asked about the emails, Chinese Foreign Ministry spokesman Hong Lei told a daily news briefing the media had "already had a lot of coverage" of Lee's case and that he had nothing else to add.
Lee and four associates went missing over the past half year, sparking fears Chinese authorities were overriding the "one country, two systems" formula protecting Hong Kong's freedoms since its return to China from British rule in 1997.
Lee said on Chinese television last week that he had not been kidnapped but had sneaked into China illegally to help with an investigation. Mainland authorities were treating him well, he added.
He also said he planned to renounce his British citizenship.
His statement came after a British Foreign Office report last month said it was likely Lee had been "involuntarily removed" to mainland China from Hong Kong.
Gui, Lee and another colleague remain in custody at an undisclosed location in mainland China. In a tearful confession on Chinese state television in mid-January, Gui said he had voluntarily turned himself in to mainland authorities.
His daughter, Angela Gui, told Reuters at the time the confession appeared "ridiculous" and contrived. Angela Gui, who was born and raised in Sweden and is now studying in Britain, told Reuters she believed Lee had been pressured into making his recent confession.
Lee wrote an email to Angela Gui asking if she knew that her father, who disappeared from the Thai resort of Pattaya in October, had been missing for more than 20 days.
In the series of emails forwarded to Reuters by Angela Gui, dated from November 10-15, Lee appealed to her to take her father's disappearance to international human rights groups.
"According to (Gui's wife's) words retold by the watchman of the building, he left the apartment with several men who claimed to be his friends," Lee said in the email.
"Perhaps you can do something, and there are a lot of (Gui's) friends ready to help if you need them. Do tell me what you think and what you want us to do."
Lee, who is at an undisclosed location in mainland China, could not be reached to verify the contents of the emails in his name.
Two of Lee's colleagues returned to Hong Kong on Friday and Sunday, refusing to discuss their cases. They also asked police in the city to dismiss their missing person reports.
In 2014, Hong Kong was rocked by street protests calling for democracy and denouncing China's plan to screen candidates for the 2017 election for its next leader.
The 79 days of demonstrations, in which student-led activists blocked key arteries, became the biggest political challenge to Beijing's Communist Party leaders in years.
Additional reporting by Clare Baldwin and Greg Torode, and Jessica Macy Yu and Ben Blanchard in BEIJING; Editing by Nick Macfie