Bestselling novelist Dan Brown has just published his latest thriller “Origin.” But Brown, among the highest-paid writers in the world, is facing the prospect of a new plagiarism lawsuit for copyright infringement from New England author Jack Dunn, who alleges the 2003 global bestseller “The Da Vinci Code” includes scenes, plots and storylines copied from Dunn’s 1997 novel “The Vatican Boys.”

A Massachusetts federal judge dismissed an earlier copyright infringement case brought against Brown by Dunn in 2007. Dunn tells MarketWatch he is reviving his plagiarism claims against Brown’s publisher Penguin Random House and is preparing to issue a new case for copyright infringement, this time in the U.K. High Court.

Dunn has hired full service London-based law firm Keystone Law. In a letter to Penguin Random House, Keystone stated they intended to issue proceedings for copyright infringement unless they received a credible explanation from Brown and his researcher wife, Blythe Brown, for what they perceive to be extraordinary similarities in both works.

Keystone Law’s letter stated: “There are hundreds of similarities between “The Vatican Boys” and “The Da Vinci Code” which comprise copying portions of TVB [“The Vatican Boys”] in the form of storylines, plots, characters, historical information, scenes, themes and even factual error which have been appropriated from TVB by Mr. and/or Mrs. Brown in writing The TDC [“The Da Vinci Code].”

The letter also concludes with the following: “There are parts of TDC which so closely replicate TVB that the impression is created that Mr. and Mrs. Brown wrote their book with our client’s book open next to them. It is however the copying by Mr. Brown of elements of TVB which contain factual errors however removes any doubt that copying took place.”

The response Keystone Law received from Penguin Random House’s solicitor’s Carpmaels & Ransford “rejected the allegations entirely” and cited “the parties’ previous litigation history” as well as previous U.K. litigation against Random House brought by authors Michael Baigent and Richard Leigh. The pair lost their lawsuit against Random House in 2006 which claimed Brown had “appropriated the architecture of their 1982 book ‘The Holy Grail.’”

Penguin Random House and Dan Brown’s agent, Heide Lange, didn’t respond to requests for comment.

Dunn told MarketWatch he is now finalizing legal evidence in preparation for issuing copyright proceedings against Brown. Dunn, who is from Western Massachusetts, said “The Vatican Boys” was sold around New England upon publication, and he said he suspects Dan Brown read his book while he was living in Portsmouth, New Hampshire in the late 1990s.

Author Jack Dunn Ann Ghanni

Judge Michael Ponsor threw out Dunn’s claim in 2007, saying: “No prior case recognizing a theory of copyright infringement based on the sort of thematic or structural similarity posited by the plaintiff has been offered in his memorandum opposing summary judgment, nor has the court found one.” Judge Ponsor is himself now a crime novelist.

Dunn said, “The claim in London is over the sequences of incidents in the respective novels which was not properly done in the United States because the judge disregarded what we gave him.”

“They [Penguin Random House] made it clear in the letter they do not want to address textual aspects but when you look at ‘The Da Vinci Code’ and ‘The Vatican Boys’ there are such close similarities. In the last nine months we have found multiple instances of copying that were not included in the first filing in the U.S. We’re up to over 100 similarities or commonalities,” Dunn said.

“Dan Brown took huge elements from my book. Of course everybody can write about Opus Dei and have copyright protection, but in both ‘The Vatican Boys’ and ‘The Da Vinci Code’ the head of the Opus Dei hires a mercenary to find them a relic so that he can become the most powerful man in Christendom,” Dunn said.

The similarities that Dunn alleges range from the beginning of both books, where a member of a secret brotherhood is murdered because they know a secret about the Catholic Church, to the climax in the novels occurring at Opus Dei House in London where the head of Opus Dei flies in on a private jet from Rome in search of a relic.

Dunn, a practising Catholic, did not include a relationship between Jesus and Mary Magdalene in “The Vatican Boys,” unlike in “The Da Vinci Code.” But he said, “Dan Brown works to a ‘Da Vinci Code’ formula, but it’s my formula.”

Dunn is a businessman as well as a writer and was put in touch with media lawyer Jonathan Coad at Keystone Law via a mutual acquaintance he met at a trade show in Germany last November.

Asked about why it has taken him over a decade to file a new claim, Dunn said: “After the judge kicked it out, I got a letter from Random House attorneys saying they were going to nail me for heavy-duty losses unless I signed off. I was tired and signed off.”

He added: “We’re going to proceed as quickly as possible and put the evidence in order. There’s a lot of work to do in the next three to four months. If we avoid strike out, hopefully the case will go to trial and the truth will finally come about this.”