...that Jesus was married to Mary Magdalene and had children. The Daily Mail also reports:
Of those questioned in the poll for the Da Vinci Code Response Group, 60 per cent of people who had read the book believed there was truth to the suggestion, compared with 30 per cent who hadn't.
Readers of the blockbuster were also four times more likely to think Catholic organisation Opus Dei, which features in the novel, was a murderous sect than those who hadn't read it.
Almost one in three believe the Priory of Sion was a real medieval organisation, when it was actually a twentieth century hoax. Only six per cent of non-readers believe it existed.
The book has been hugely popular in Britain, with 22 per cent of adults having read it, the survey of 1,000 people by Opinion Research Business found.
The DVC Response Group, which is made up of priests, monks theologians and members of Opus Dei, wants the film adaptation of the novel to carry a disclaimer making it clear it is fiction.