The authors want to talk about Christ. They want you to know that, buried beneath centuries of misinformation and conspiracy, Jesus had a secret wife, named Mary Magdalene, and he fathered two children with her. And they want you to know that their book on the matter, named the “Lost Gospel,” is on sale soon for $21.74. “If true,” reported the Daily Mail in an overheated dispatch, “this would make it the greatest revelation into the life of Jesus in nearly 2,000 years.”

Indeed. If true. But is this just the latest theory of an embattled researcher?

Rekindling one of the Jesus Christ’s greatest mysteries, a la “The Da Vinci Code,” the new book draws from a 1,500-year-old Aramaic-language manuscript found inside the British Library. There, the authors say, the secrets of Jesus’s family life have been in plain sight for more than a century.

“What the Vatican feared — and what [“Da Vinci Code" author] Dan Brown only suspected — has come true,” begins the book, authored by York University (Canada) professor Barrie Wilson and documentarian Simcha Jacobovici.

“There is now written evidence that Jesus was married to Mary the Magdalene and that they had children together…. Gathering dust in the British Library is a document that takes us into the missing years of Jesus’s life…. According to the document that we uncovered, sometime during this period he became engaged, got married, had sexual relations, and produced children. Before anyone gets his/her theological back up, keep in mind that we are not attacking anyone’s theology. We are reporting on text.”

The text in question is called the Ecclesiastical History of Zacharias Rhetor, written on treated animal skin, which was brought to the United Kingdom in 1847 when the British Museum bought it from an Egyptian monastery. Scholars scrutinized the document and discarded it as insignificant.

Then, years ago, Wilson and Jacobovici gave it a look and began to suspect otherwise. The Sunday Times quoted Wilson describing it as an “ancient Syriac manuscript lurking in the British Museum…. Scholars have known about it for almost 200 years, but have not known what to make of it.”

But these authors, who are expected to answer questions on Wednesday at the British Library, did. They claim the meaning of the text had been shrouded in code and “embedded meaning.” It speaks of a figure named Joseph, who apparently bore striking similarities to Jesus. He was depicted as “savior-figure,” the book said. “Joseph, like Jesus, was assumed dead and turned up alive; he too had humble beginnings and ended up a king of sorts.” So they contend Joseph was really Jesus in the text.

And this Joseph, they said, had a wife named Aseneth, whom they purport represented Mary Magdalene. “Put simply, in order to convey the stature of Aseneth — perhaps Mary the Magdalene — to his audience, the unknown author of our manuscript selected a dominant image … he could be sure his readers would readily understand.”

The book’s purported findings, however, tell only part of the story. Jacobovici, widely known in the theological community, has already come under criticism for pursuing theories of early Christianity that many scholars have dismissed. The controversy is a subplot to the grander drama surrounding the study of Jesus’s life, illustrating the tug-and-pull between popular interest, entrenched doctrine, the potential for big payouts and the limits of academic inquiry.

In 2002, Jacobovici, a Canadian filmmaker who studies biblical archaeology, pushed out a documentary that hailed a seemingly pivotal relic called the James ossuary, which allegedly showed that Jesus had a family. Its owner was indicted on charges of forgery. Archaeologists from Israel to the United States denounced the ossuary as a hoax.

“It’s a publicity stunt, and it will make these guys very rich,” University of Arizona archaeologist William G. Dever told The Washington Post in 2007. “And it will upset millions of innocent people because they don’t know enough to separate fact from fiction.”

Jacobovici went on to author other works that were called out for veering into untruth. One imbroglio spilled over into the courts, with Jacobovici suing a critic for libel. Jacobovici fumed in an interview with Time: He “crossed the line from fair comment to outright libel. Specifically, he has accused me repeatedly — verbally and in writing — of ‘forging archaeology.'”

Then a group of academics from Duke University to Columbia University to Tel Aviv University wrote a joint letter in 2008 that cast suspicion on his work involving the Talpiot tomb, which Jacobovici claimed showed Jesus had a family. The letter, signed by 17 academics, called Jacobovici’s work “controversial” and disputed his assessment that one archaeologist’s widow had “vindicated” his claims about the relics.

“We wish to protest the misrepresentation of the conference proceedings in the media,” the letter said. “And make it clear that the majority of scholars … either reject the identification of the Talpiot tomb as belonging to Jesus’s family or find this claim highly speculative.”

So what about this most recent one?

“It sounds like the deepest bilge,” Diarmaid MacCulloch, an Oxford University professor told the Sunday Times. “I’m very surprised that the British Library gives these authors houseroom.”

Correction: The original version of this story incorrectly stated that the Discovery Channel listed James ossuary as a scientific hoax. We regret any impression that the channel was distancing itself from Jacobovici’s film.