A Hong Kong publisher whose disappearance last year sparked an international scandal and street protests has reappeared, making a televised “confession” on China’s government-controlled broadcaster CCTV.

Gui Minhai, a 51-year-old Swedish citizen who specialised in salacious tomes about China’s Communist party elite, vanished from his beachfront home in Thailand in October last year.

His disappearance – and the apparent abductions of four other booksellers with whom he worked – was widely suspected to be the work of Chinese security forces, although Beijing repeatedly refused to comment on the whereabouts of the missing men.

Earlier this month thousands of demonstrators took to the streets of Hong Kong, a former British colony, after Lee Bo, a British passport holder who had worked with Gui, became the fifth bookseller to go missing.

During a visit last week to Beijing, Philip Hammond, the British foreign secretary, said that if Chinese authorities had been responsible for Lee’s disappearance it would represent an “egregious breach” of Hong Kong’s supposed autonomy from the authoritarian mainland.

The motive for the disappearances remains a mystery but Gui and Lee are understood to have been preparing to publish a book about the private life of Xi Jinping, China’s president.

On Sunday night China finally broke its silence over the case by broadcasting what it said was a confession made by Gui on state broadcaster CCTV.

#BREAKING HK bookstore owner Gui Minhai, reportedly missing, turns himself in for hit-and-run 11 years ago (Xinhua) pic.twitter.com/IGA4zpDJ2C — CCTVNEWS (@cctvnews) January 17, 2016

The publisher claimed he had voluntarily surrendered to Chinese authorities in October last year over his supposed involvement in a fatal hit-and-run incident in the city of Ningbo in December 2003.

Gui said he had fled mainland China after the incident, in which a young woman was killed, but had been driven to return last year out of guilt and a sense of longing for his homeland. “It is my own choice to come back and to confess my crime. It is nobody else’s business. I need to take responsibility for it myself,” he said in the televised confession.

Gui had last been seen in security footage shot outside his flat in Thailand last October. There was immediate scepticism among China experts and human rights activists over the “confession” – the latest in a series of such broadcasts, in which Communist party opponents have appeared since Xi came to power.

Chinese justice at its finest https://t.co/MtlQrbVr4q — Christopher Balding (@BaldingsWorld) January 17, 2016

William Nee, Amnesty International’s China researcher, said: “Even if this story is true – which is a big if – it still leaves many unanswered questions.

“Why would four other employees of a company need to go missing in order to assist with a regular criminal case? How could other missing or otherwise investigated colleagues of Gui Minhai have any connection to the case? What form of detention is Gui Minhai held under? Has he had access to legal counsel or consular visits, and if [not], why not?”

Before his disappearance, Gui had become a major irritant for China’s leaders. He specialised in sketchily sourced tabloid-style tomes about the private lives of senior party officials – including one book chronicling the alleged sexual escapades of Bo Xilai, the former Chongqing party chief, whose wife was jailed for the murder of British businessman Neil Heywood.

Another well known volume examined the private life of Zhou Yongkang, China’s once feared security tsar who was jailed for life for corruption earlier this year. Recent months had seen Gui’s publisher produce a flurry of books about President Xi.

The CCTV report did not disclose where Gui was being held. Xinhua, China’s official news agency, said the publisher was also suspected of other unspecified crimes.

