Jesus married the prostitute Mary Magdalene and had children, according to a manuscript almost 1500 years old unearthed at the British Library.
The so-called Lost Gospel, which has been translated from Aramaic, allegedly reveals the startling new allegations, according to The Sunday Times (behind a paywall).
Professor Barrie Wilson and writer Simcha Jacobovic spent months translating the text, which they claim states Jesus had two children and the original Virgin Mary was Jesus's wife and not his mother.
Many experts have downplayed the biblical figure's historical importance but, according to the translators of the new gospel, she is of much greater significance than previously thought.
Mary Magdalene already features in the existing gospels and is present at many of the important moments recorded in Jesus's life.
The Lost Gospel is not the first to claim that Jesus married Mary Magdalene.
Both Nikos Kazantzakis in his 1953 book The Last Temptation of Christ and, more recently, Dan Brown in The Da Vinci Code made the same allegation.
Further revelations from the book, including the names of Jesus's children, will be released this week.
The publisher, Pegasus, has confirmed the press conference will go ahead as planned.
- The Independent