STOCKHOLM (Reuters) - A bookseller detained in China for publishing books on the personal lives of President Xi Jinping and other Communist Party leaders has won a prize for free speech and press freedom awarded by a Swedish media organisation.

Members from the pro-democracy Civic Party carry a portrait of Gui Minhai (L) and Lee Bo during a protest outside the Chinese Liaison Office in Hong Kong, China January 19, 2016. REUTERS/Bobby Yip

Gui Minhai is one of five Hong Kong booksellers who went missing in 2015 and later appeared in mainland Chinese custody. The four others have returned to Hong Kong. [nL4N19A038]

Awarding him the annual Anna Politkovskaya Memorial Prize, Publicistklubben said Gui had “despite personal risk ... shown great courage as a publisher and challenged the narrow-mined political agenda of the Chinese regime”.

The arrest of the five men prompted fears Beijing may be eroding the “one country, two systems” formula under which Hong Kong has been governed as a special administrative region since its return to China from British rule in 1997.

Publicistklubben said Gui, a Chinese-born Swede, was abducted in Thailand while on holiday and his family did not know where he was being held.

“I am glad that this prize will focus attention on my father’s situation,” the prize givers quoted his Swedish daughter, Angela Gui, as saying.

“Hopefully, more attention ... can lead to more information on his situation and health and that (he) will be treated better.”

Chinese Foreign Ministry spokesman Lu Kang, asked about the award, said he had “no interest” in commenting on what non-governmental groups got up to, and that he had no idea about the prize. He did not comment further.

China has said its law enforcement officials have done nothing illegal with regard to Gui.

The prize is named after Anna Politkovskaya, a Ukrainian journalist best known for reporting on human rights violations in Chechnya who was murdered in Moscow in 2006.