Director Ron Howard has accused the Vatican of trying to hamper the filming of his new movie, Angels & Demons, starring Tom Hanks. The movie sequel to author Dan Brown's The Da Vinci Code features symbolist Robert Langdon helping to rescue four kidnapped cardinals. But Howard said the Vatican exerted its influence "through back channels" to prevent filming near certain churches. A Vatican spokesman said the director's claims were purely a publicity stunt. "Everything progressed very smoothly, but unofficially a couple of days before we were to start filming in several of our locations, it was explained to us that through back channels and so forth that the Vatican had exerted some influence." Last summer, Rome's diocese confirmed it had barred producers from filming inside two churches because the movie did not conform to the church's views. The director also claimed the Vatican got an event related to the film's premiere in Rome cancelled. "There was supposed to be a reception or screening here in Rome that had been approved and I suppose that the Vatican had some influence over that," he said. Speaking to the Associated Press the Vatican spokesman, the Reverend Federico Lombardi, refused to comment on Howard's allegations about church interference, saying his charges were purely designed to drum up publicity for the film. Catholic critics were unhappy with The Da Vinci Code which suggests that Jesus married Mary Magdalene and had children, creating a royal bloodline that Church officials kept secret for centuries. But Howard challenged them to see the new movie before condemning it. "My only frustration as a film-maker is that we actually reached out a couple of times, to sort of offer opportunities for bishops and others just to see the film. And those opportunities have all been declined," he said. "So far all the criticism, all of the complaints about the film have been coming from people who haven't seen it." Over the weekend, a 102-year-old Italian bishop was quoted in the Italian media calling the film "highly denigrating, defamatory and offensive to Church values". However, the storyline of Angels & Demons does not raise questions about Jesus Christ - it is billed as a "science vs religion" thriller that deals with an attempt to hijack a papal election. Howard's adaptation of The Da Vinci Code, which was panned by critics, earned more than $750m (£505m) at the box office worldwide. Angels & Demons will be released in the UK on 14 May.