These are books that one might buy at a newspaper stall on a weekend, on the way to one of the many dim sum restaurants in Hong Kong, to while away an hour or two over tea and siew mai.
So says a PhD student of Chinese studies, Mr Hung Tak Wai, 24, who reads these books occasionally for their entertainment value. "They have information of which you may ask 'is it true this time?' " To the University of Hong Kong student, it is a way to "spend some time away from serious study materials".
For these books that purport to give the insider low-down on the political struggles within the Chinese Communist Party (CCP) and the private lives of Chinese leaders are quite readable. They also come with titles that are nothing short of sensational: Zeng Qinghong Plots To Assassinate Xi Jinping; Jiang Zemin Under House Arrest; Xi Jinping To Collapse in 2017.
"A lot of their content is made up... it is somewhere between fiction and non-fiction," says the discerning Mr Hung in a phone interview. He adds, however, that many of his mainland Chinese colleagues at university trust the contents of the books and lap them all up, even buying them for friends and relatives back home as presents.
Indeed, the biggest buyers of such books - banned in China - are not the Hong Kongers themselves but mainland Chinese tourists. They frequent bookshops such as the Causeway Bay Books, whose booksellers recently landed in hot water for peddling such works.
A co-owner of the bookshop and the publishing house Mighty Current, Mr Lee Bo, disappeared in Hong Kong while four others, including his business partner, Mr Gui Minhai, disappeared while in Thailand and mainland China. They are all believed to be under detention on the mainland.
"For the past 10 years, and particularly in the past three to four years, more... have been coming across the border simply to buy these books, and not necessarily for tourism. They have a book list in hand," said political analyst James Sung of City University of Hong Kong.
The Chinese read the books for the light they claim to shed on the power struggles within the CCP, which is opaque in its processes, but also to satisfy their prurient curiosity about the romantic affairs of the top leaders. "People are interested in how (President) Xi Jinping could marry a beautiful wife" like Ms Peng Liyuan, who is much younger than him, said Dr Sung.
Even leaders who have long left the political scene are grist for the writers' mill, including the revered first Prime Minister of China Zhou Enlai, who died in 1976. A new book, published last month, speculates that some puzzling aspects of Mr Zhou's life - such as his coolness towards his wife at the time of their marriage and his careful loyalty to Mao Zedong - were due to his homosexuality.
Written by a former editor of the liberal Open magazine, Ms Tsoi Wing-mui, The Secret Emotional Life of Zhou Enlai offers little hard evidence to prove Mr Zhou's homosexuality. One is a diary he kept as a young man in which he professed to be in love, in an entry that had several characters blacked out.
Ms Tsoi moved to Hong Kong from the mainland in 1980 and many writers of this genre of books are thought to be from China, although it is hard to know as many of the authors use pen names. Some writers, however, are well known to readers. These include Yu Jie and Chen Pokong, both based in the United States.
Dr Sung said many of these writers may live outside China, but they "maintain a vibrant connection with relatives and friends, and even cadres inside China... who provide them with information".
Books on the CCP and its leaders are not new in Hong Kong, there having been a wave of such books around 1997 when Hong Kong was handed over by the British to China under the "one country, two systems" formula that guaranteed a high level of autonomy and freedom of expression in the city.
In the earlier days, however, the books were better written and researched, noted bookshop owner Wong Sheung Wai, 70, whose store does not carry the genre.
With the voracious appetite of the mainland Chinese, Hong Kong publishers have shortened the time taken to publish these books. The effect is that their content is simple and lacking in rigorous research, said Mr Wong.
The big question now is how long more such books can be published in Hong Kong and how far the writers can go in their exposes. Mr Yu Jie, 42, with more than 30 books to his (real) name, was in talks with publisher Yiu Man-tin to publish his book China's Godfather, Xi Jinping when Mr Yiu was arrested in Shenzhen in October 2013 and later sentenced to 10 years' jail for "smuggling goods".
The book was later published by Open, which was recently in talks with Mr Yu to publish his second book on Mr Xi, titled Xi Jinping's Nightmare. Earlier this month, after the disappearance of Mr Lee, Open's chief editor, Mr Jin Zhong, wrote him to break off the book deal. Mr Jin asked for the writer's understanding, saying: "I am not able to face the huge consequences." Mr Yu found a publisher in Taiwan and the book will be out next month.
For the CCP, these books, which contain rumours and incorrect information, project a negative image of the party and its leadership, said Dr Sung. If no action is taken, more of such books will come out that will expand their subjects to include even the military, he added. This was why some booksellers disappeared.
There is also a sense that the factional struggles on the mainland are being extended to Hong Kong through these books, with some critical of Mr Xi - such as Mighty Current's Xi Jinping's Dream Of A 20-year Rule, which accuses him of trying to extend his rule beyond the traditional 10-year tenure of the country's top leader - and some attacking his opponents.
In an article on Thursday on the blog site of the Hong Kong Economic Journal, former Straits Times journalist Ching Cheong wrote that the CCP decided to curb Hong Kong's market of banned books because it was worried that it would constitute a threat to its legitimacy and its security as rulers of the country.
The irony is that Hong Kongers have little interest in the books.
Physiotherapist Emily Law, 40, who has not read any of the books, is now looking for one, not because she is interested in the peccadilloes of Beijing's leaders, which are too remote for her to care about, but because she wants to know what led to the booksellers' disappearance.
"We are just concerned about our future and we want to ask for freedom and democracy," she said.
This article was first published on Jan 17, 2016.
Get a copy of The Straits Times or go to straitstimes.com for more stories.