It was the worst possible first impression to enshrine in the minds of millions worldwide: that of a mysterious, secretive, cult-like movement whose extreme religious practices were personified by Silas the Albino - the murderous, self-flagellating monk who stopped at nothing in his quest to protect the Holy Grail. While the success of Dan Brown's The Da Vinci Code is a publishing phenomenon, each of the 40m copies sold represents a PR disaster for the organisation known as The Prelature of the Holy Cross and Opus Dei, or, more simply, Opus Dei ("Work of God"). It is likely that Brown introduced many of his readers to the group.

If you have been to an airport or a train station in the past 12 months, you will have seen someone reading a copy. Which for Opus Dei means yet another accusation of "brainwashing, coercion and a dangerous practice known as 'corporal mortification'," as described in the book's preface. Self-flagellation, to you and me.

The book's impact has been nothing short of seismic, yet it could be eclipsed by the forthcoming screen adaptation, directed by Ron Howard and starring Tom Hanks. Once again, the organisation's 86,000 members will find themselves caught in the glare of publicity.

First impression

And so Opus Dei is launching a pre-emptive media strike of its own. "There's a huge contrast between the way we're portrayed and the way we are in reality," says Brian Finnerty, director of media relations for the United States division. He is one of two full-time staff who run the communications office in New York.

A former journalist with the Los Angeles-based Investors Business Daily, Finnerty has been a member of Opus Dei since 1985 and has overseen the organisation's increasing embrace of the media since 1995. "We consulted with various friends and experts in PR who were willing to help us out. They told us how to show the world that Opus Dei is about ordinary Catholics trying to get closer to God in their daily lives, and that we're happy to share that with people."

However controversial Opus Dei's vision of religion may be - it promotes the principle that holiness can be found through everyday tasks - it now comes complete with all the trimmings of 21st century marketing. The fact that it even boasts boasts a press office may come as a surprise to anyone whose first impression is derived from Brown's story.

Yet the aim is to ensure that the release of the movie actually works in the organisation's favour. "The Da Vinci Code has a tremendous upside for Opus Dei," says John Allen, the Vatican correspondent for the National Catholic Reporter and author of Opus Dei: An Objective Look Behind the Myths and Reality of the Most Controversial Force in the Catholic Church. "Yes, it's a tremendously negative representation and it fuels conspiracy theories about them. Yet it has given them a worldwide visibility that no amount of money could ever purchase. You're talking about 86,000 people, one of the smaller groups inside Roman Catholicism. That's the same number of Catholics that are on the island of Tasmania. And now they have an enormous global profile."

One benefit is that Doubleday, the publisher of The Da Vinci Code, is set to release Opus Dei founder Saint Josemaría Escrivá's book The Way a week before the movie. No such co-operation was to be had with Sony Pictures, however, which Finnerty says refused to communicate with the organisation. "Our response to that has been 'OK, fine'. The movie is a fact and so we may as well use this fact to talk about what Opus Dei really is and what the Catholic church really is."

Big event

And talk they do: far from conforming to its stereotype as a defensive, underground and obscure clique, Opus Dei is on a global charm offensive. Representatives have given interviews on the Today Show, Good Morning America, Meet the Press and Fox News, while the organisation has been involved in various documentaries, including projects with the History Channel and Channel 4. Its website, www.opusdei.org, received over 1 million visitors last year, while a blog written by Opus Dei member Father John Wauck poking fun at The Da Vinci Code is being promoted.

"In terms of the way they now package themselves, [Opus Dei] has become a very professionally run operation," says Allen. "It's evident that the media is very important to them and they see the movie as the next big event. They're currently trying to get on top of it."

Last week the organisation even introduced the world to a member it hailed as "the real Silas." In an attempt to counter Brown's portrayal of Opus Dei members as deviants who dress like Friar Tuck and whip themselves raw, Silas Agbim is a happily married Nigerian-born stockbroker who lives in Brooklyn. Agbim is the current poster child for the practices that sit uneasily in the glare of the media spotlight. Opus Dei says that members only wear the spiked "cilice" for two hours each day or practise corporal mortification once a week with a small piece of cord while reciting prayers.

It is a giant leap compared to how the organisation behaved in the wake of the controversy surrounding Pope John Paul II's beatification of Josemaría Escrivá in 1992. Accusations flew of cult-style manipulation, encouragement of physical self-harm and having historical links with General Franco's fascist rule in Spain. Opus Dei reduced its reputation further by stonewalling critics. "We couldn't handle the PR aspect because we were caught a little flat-footed," says Finnerty. "It was a major wake-up call for us."

Yet when further controversy erupted over the canonisation of Escrivá in 2002 - only 27 years after his death - the movement took the opportunity to embrace it. "The difference today is that they take phone calls," says Allen. "The great irony is that today Opus Dei has far and away the best communications of any sub-group in the Catholic church."

The organisation is going to need it in the coming months as the inevitable counterattacks are launched. The media furore surrounding Education Secretary Ruth Kelly's admission last year that she used the teachings of the organisation for "guidance" speaks volumes about its public reputation.

Boosts sales

The trick for Opus Dei, of course, is to walk a fine line - projecting a positive image without promoting the film.

"You can argue that any time I open my mouth I'm helping sell the novel and the movie," says Finnerty. "But my biggest concern is whether or not people know the truth about Opus Dei and the truth about the Catholic Church. So if I can say something that boosts sales of the movie yet also increases knowledge of the truth about Opus Dei, I'm quite happy to do it."