LATE night, an empty road, a car. A man and a woman speed towards a head-on collision which will kill one of them and burn an unforgettable image into the mind of the other.

It sounds like the pitch for a movie but, while film is at the heart of it, this story is very real indeed. The place is Holland, the year 1976, the date August 13 - a Friday, as bad luck would have it. The man is designer John Richardson, currently working on Richard Attenborough's second world war epic, A Bridge Too Far, but most recently employed as special effects consultant on supernatural chiller The Omen. The woman is Liz Moore, his assistant. In a few moments she'll be dead, cut in half when the car's front wheel slices through the chassis and into the passenger seat. Richardson will survive to tell the tale - and quite a story it is too.

Less than a year earlier, he had masterminded the parade of gruesome deaths which had made The Omen a box office smash, among them the decapitation of a photographer played by David Warner. And, like everyone else who had worked on the film - including stars Gregory Peck and Lee Remick - he was well aware of the whispers and rumours which had surrounded its filming. There had been talk of a hex, a curse, a hoodoo.

Did he believe it? Not then, perhaps. But as he came to in the minutes after the crash, he saw something that must have chilled him to the bone: his passenger, dead from injuries which bore an uncanny resemblance to the ones he had prepared for Warner. And a road sign marking the distance to an otherwise insignificant Dutch town. It read: Ommen, 66.6 km.

Today, Richardson is sanguine about his experience. Others are less inclined to forget theirs. Producer Harvey Bernhard, well aware of the Hollywood gossip that had The Omen lined up as the latest in a long line of cursed films, started wearing a cross on set. "I wasn't about to take any chances, " he says 30 years later. "The devil was at work and he didn't want that film made. We were dealing in areas we didn't know about and later on in the picture it got worse, worse and worse."

Bob Munger, the man who came up with the idea for the film, had misgivings even before production started. "I warned Harvey at the time. I said, 'If you make this movie you're going to have some problems. If the devil's greatest single weapon is to be invisible and you're going to do something which is going to take away his invisibility to millions of people, he's not going to want that to happen'."

He was right to be worried. In June 1975, just two months before filming was due to begin, Gregory Peck's son had killed himself with a bullet to the head. The actor set off for London in September in a sombre mood which wasn't much soothed when his plane was hit by lightning high above the Atlantic. A few weeks later, executive producer Mace Neufeld also left Los Angeles. You think lightning doesn't strike twice? It does in this story. "It was the roughest five minutes I've ever had on an airliner, " says Neufeld. The curse of The Omen had begun.

There was much more to come. The hotel in which Neufeld and his wife were staying was bombed by the IRA. So, too, was a restaurant where the executives and actors, including Peck, were expected for dinner on November 12. A plane they had been due to hire for aerial filming was switched to another client at the last minute and crashed on take-off, killing all onboard. A tiger handler died in a freak accident.

Even when filming finished, the curse seemed to follow the actors and technicians to different projects.

Richardson we know about, but the story of stuntman Alf Joint is almost as chilling. He too went to work on A Bridge Too Far, but was badly injured and hospitalised when a stunt went wrong. He only had to jump from a roof on to an airbag, an average day's work for someone like him. But this time, something odd happened. He appeared to fall suddenly and awkwardly.

When he woke up in hospital, he told friends he felt like he had been pushed.

These and other stories surrounding The Omen have now been collected for a Channel 4 documentary, The Curse Of The Omen. Producer Alan Tyler admits that he was as sceptical as anyone else when researching the project, but says he was gradually convinced by the facts.

"What we were really shocked by is that, while there are some aspects of it where you can say, 'I don't really buy that', the further into it you go, the more you're not sure. So we went from being quite cynical to at least having doubts."

Tyler and his team interviewed Bernhard, Neufeld and Munger as well as director Richard Donner, actor Billie Whitelaw and Richardson himself. Harvey Stevens, the young English boy who played the demonic Damien, will not speak about the hex, and Gregory Peck never went on record about it.

But, says Tyler, "The crew that we spoke to had a sense that everyone involved in the production was freaked out to some extent. They all felt that something wasn't quite right and that included the cast. These were seasoned professionals - they had seen a lot of productions and doubtless a lot of production accidents. Yet they themselves pick this film, more than any other, as having something extraordinary about it."

Of course, as Tyler's scepticism demonstrates, stories of cursed films have been around almost as long as there have been publicists to make them up. What better way to market a film than mention a curse associated with it? What better way to boost longevity, especially in the age of the internet, where conspiracies and cults grow like digital lichen?

And, of course, where curses are concerned, we're all willing participants.

"People really want to believe, " says Adele Hartley, director of Dead By Dawn, Scotland's international horror film festival. "Everyone feels a little guilty about toying with the supernatural, they think maybe we are opening some doors we shouldn't, so it's very tantalising. I'm almost a believer."

Yet some of the stories simply defy explanation, cannot be explained by chance alone. For instance each of the three Poltergeist films was marked by a death - the murder of lead actress Dominique Dunn in 1982, a year after the release of the first film; the death of actor Julian Beck in 1985, as production on Poltergeist II began; and the death of 12-year-old actress Heather O'Rourke from septic shock less than a year after the release of Poltergeist III.

So what are the ingredients of a good hex and how do we sort the real from the press release? For Mitika Brottman, author of Hollywood Hex, a new book about cursed films, you need a Poltergeist-style gumbo of death, disaster and hard-to-explain events for the rumours to start in the first place.

"A film will appear to be hexed if one or more of the stars has died after filming or during filming or if it turns out that the stars have drug or health problems or suicidal tendencies - something that the audience wasn't aware of at the time. Or if there's been an unusual pattern of co-incidences associated with the film such as a series of deaths or a series of accidents during filming. If a film falls into this pattern, then it's subject to all sorts of scrutiny so that people find all kinds of other co-incidences, " says Brottman.

Predictably, two of the most famous cursed films are also two of the scariest and most controversial: The Exorcist (1973) and Rosemary's Baby (1968).

"With those films, " she says, "the correlation between events inside the film and events outside it are just so uncanny, " says Mikita Brottman. "A genuine hex is when you simply can't watch a film without being aware of those extra circumstances."

The Exorcist stories turn on the subsequent travails of Linda Blair, the child actor who played the 12-year-old girl who is possessed by a demon. In 1977, aged 18, she was arrested on drugs charges. Since then she has variously gone into hiding and claimed that her experience on the film has made her resolve never to have children. Beyond that, cases of psychological disturbance among viewers are legion: the most infamous "fan" of the Exorcist movies being gay American serial killer Jeffrey Dahmer. He was obsessed with Exorcist III, watching the film over and over again before killing his victims. It was playing on his video when police finally arrested him.

Even more disturbing are the stories surrounding Rosemary's Baby. Roman Polanski's 1968 film told the story of a young Manhattan woman whose husband trades their unborn child in a Faustian pact with a group of devil worshippers. A year after its release, Polanski's own wife, the actress Sharon Tate, was murdered by the Manson Family. Tate was pregnant with the couple's first child when she died.

Chillingly one film critic, reviewing the film before her murder, described the satanists as resembling "a small, far-out Californian religious sect."

But even before Sharon Tate's death, producer William Castle has begun using the c-word. In April 1969, days after receiving death threats and hate mail relating to the film, Castle is rushed into hospital with kidney failure. At one point he cries out "Rosemary, for God's sake drop that knife." As he convalesces, he discovers that in the same hospital is Krzysztof Komeda, the Polish composer who wrote the score for the film and an old friend of Polanski's and Tate's. Komeda will die of a brain clot before the month is out, a death which echoes that of Rosemary's friend Hutch in the film.

Two years later, Polanski would undergo his own form of exorcism by tackling a film version of Shakespeare's Macbeth, most memorable for a scene in which Lady Macduff and her children are murdered on Macbeth's orders. It was a brave attempt at catharsis, but the stain of the Manson tragedy and the Rosemary's Baby curse has remained with him.

Although fictitious where Polanski is real, Superman is another who has been scratched at by the Fates. Actor George Reeves, who played the Kryptonite-fearing superhero on television in the Fifties, died of a single gunshot wound in mysterious circumstances in 1959. Most said suicide; some said murder. Two decades later Christopher Reeve took on the role and was himself paralysed after a riding accident. His co-star, Margot Kidder, later suffered psychosis. It's worth noting that the director of the first Superman film was Richard Donner, fresh from The Omen.

Today Kidder is unconvinced by talk of a hex. "With any group of people in life, sad things happen, and crazy things, and happy things, " she has said. "When you're in the public eye, it's just amplified, that's all. There's no curse."

Right. So how do you explain the continued problems the Superman franchise has suffered? Throughout the Nineties, a mooted fourth Superman movie was beset by problems, to the point that in 2003 stories began to circulate of Hollywood agents refusing to put up their clients for the role, so wary were they of the hex. Brett Ratner and Tim Burton were among the directors who joined the project only to pull out later. However the film has finally started shooting with director Bryan Singer at the helm, and is due for release next year. An unknown called Brandon Routh is stepping into the perilous red pants.

It was another Brandon whose demise gave rise to one of the most chilling curse stories of recent years. Brandon Lee, son of kung-fu star Bruce Lee, died on the set of The Crow in 1993 in circumstances eerily similar to the plot of the film his father was making when he died in 1973.

In that film, Bruce Lee is shot with a gun he thinks is unloaded; his son dies in 1993 when he's shot by a gun that is supposed to be loaded - but with blanks. To this day, nobody really knows how a real bullet found its way on to a movie set. That Brandon Lee's character in The Crow is shot dead the night before his wedding and then resurrected as an avenging hero has only added to the mystique that now surrounds the film - Lee was due to marry his fiancee immediately after filming stopped.

Equally absorbing is the hex attached to Rebel Without A Cause (1955). James Dean died in a car crash, of course, but how many people know the accident happened the same weekend the film opened? Or that just weeks earlier Dean had filmed an advert for the National Highways Committee in which he can be seen asking America's young petrol heads to drive safely, "because the next life you save may be mine"?

It wasn't just Dean that the RWAC curse touched. His friend Nick Adams, who had re-dubbed some of Dean's speeches in Giant after the accident, died in 1968 from a mysterious drug overdose. Co-star Natalie Wood drowned in equally unusual circumstances in November 1981, and another RWAC star, Sal Mineo, died five years earlier in a knife fight. Troy McHenry, a Beverly Hills doctor, bought the engine from Dean's Porsche and had it installed in his own car, but was killed the first time he drove it. The list goes on.

As for Alan Tyler, did he feel that by making a documentary about the curse on The Omen, he would become part of it?

Funnily enough - "Things did happen that seemed somewhat odd, " he says. "The strangest was when we had two different camera crews filming in separate locations and yet all the footage had the same fault. We just couldn't figure out why that should be and it seemed to be on all the occasions when it was to do with something satanic. It did make us wonder."

You have been warned.

The Curse Of The Omen, part of Channel 4's Horror Season, is on October 26 at 11.05pm. Hollywood Hex by Mikita Brottman is published by, Creation Books, GBP14.95 and distributed by Turnaround PSL