Dan Brown's ex-wife is suing him for living a double life that included multiple affairs and him lavishing his mistresses with expensive gifts.
The Da Vinci Code author has been accused of having an extramarital relationship with a Dutch horse trainer, who he gave expensive gifts including several Friesian horses and financing her horse-training business.
In her lawsuit filed Monday in New Hampshire, Blythe Brown - who Brown divorced in 2019 after 21 years of marriage - also claimed credit for inspiring much of his work and coming up with the premise for The Da Vinci Code.
She also alleged that Brown hid future projects worth 'millions' from her, including a TV series and a children's book.
According to the Daily Mail, the lawsuit says: "Dan has lived a proverbial life of lies for at least the past six years, seeming to be the epitome of a world-famous novelist leading a simple life in his home state of New Hampshire, while in reality he was something quite different.
"For years, Dan has secretly removed substantial funds from his and Blythe's hard-earned marital assets to conduct sordid, extra-marital affairs with women - one half his age - and to pursue a clandestine life."
Brown allegedly gifted a horse worth $345,000 (£279,000), a horse transport truck and a new car to the unnamed horse trainer, which he paid for using money from their joint assets.
Blythe claims in the court filing that the affair with the horse trainer began in 2014 after she brought her to the US to train a Friesian horse owned by the Browns.
She claims that Dan 'persuaded' her that she had 'full knowledge' of the wealth they accumulated while married upon their divorce last year.
Blythe said she was only filing the lawsuit to stand up for herself and assert her "self-worth".
She said in a statement: "We worked so hard together, struggling to build something meaningful. With great success came our promises to each other that we would not let it change us or our life together.
"I don't recognize the man that Dan has become. It is time to reveal his deceit and betrayal. After so much pain, it is time for truth. It is time to right these wrongs."
Blythe also alleged that she was the one who inspired Brown to give up songwriting and focus on writing fiction.
She also said she "served as lead researcher, first-line editor, and critic, and was Dan´s literary partner in the fullest sense."
In a statement, Brown said he was "stunned" by the allegations and called the complaint "written without regard for the truth".
He said he never misled Blythe on their finances during their divorce and she ended up with half their holdings.
His statement said: "For reasons known only to her and possibly her lawyer, Blythe Brown has created through this suit a fictional and vindictive account of aspects of our marriage designed to hurt and embarrass me."
Mirror Online has contacted Dan Brown's reps for comment.