Mark Twain's autobiography is finally to be published later this year, and a section reveals his scandalous relationship with a woman who became his secretary after his wife died.
The writer, who created Tom Sawyer and Huckleberry Finn, had instructed that his autobiography should not to be published till 100 years after his death.
Mark Twain died on April 21, 1910. He left behind nearly 5,000 unedited pages of memoirs along with handwritten notes that said he didn't want them to be published for at least a century.
The Independent reported on Monday that the University of California, Berkeley, will release in November the first volume of the autobiography. The manuscript is in a vault there.
The trilogy will run to half a million words and shed new light on the American novelist.
Some scholars feel the memoir was kept under wraps as he wanted to talk freely about issues such as religion and politics, while other think that the 100-year period ensured that none of his friends will be offended.
A section of the memoir will detail his relationship with Isabel Van Kleek Lyon, who became his secretary after his wife Olivia died in 1904.
The report said Mark Twain was so close to Lyon that she once bought him an electric vibrating sex toy. She was sacked in 1909 after Twain claimed she had "hypnotised" him into giving her the power of attorney over his estate.
"Most people think Mark Twain was a sort of genteel Victorian. Well, in this document he calls her a slut and says she tried to seduce him. It's completely at odds with the impression most people have of him," historian Laura Trombley was quoted as saying.
"There is a perception that Twain spent his final years basking in the adoration of fans. The autobiography will perhaps show that it wasn't such a happy time. He spent six months of the last year of his life writing a manuscript full of vitriol, saying things that he'd never said about anyone in print before. It really is 400 pages of bile."
Robert Hirst, who is leading the team at Berkeley, said: "When people ask me 'Did Mark Twain really mean it to take 100 years for this to come out', I say 'He was certainly a man who knew how to make people want to buy a book'."