But the man who put a capital B into the contemporary blockbuster, whose films have grossed billions and whose name is usually the stamp of glorious cinematic success, has been humbled. By a button. Pushed, it seems, mistakenly.

This has had a profound effect on the director's latest opus, at least as far as the members of Bafta are concerned. By tomorrow they have to nominate the films they think worthy of accolade, and Spielberg's Munich was expected to be among them, tipped for awards both in Britain and at the Oscars.

But the preview DVD sent to the academy's members is unplayable on machines used in the UK. As a result the majority of Bafta's 5,000 voters will not have seen the film, due to be released in Britain on January 27, and can hardly be expected to recommend it for acclaim.

Sara Keene at Premier PR, the company coordinating Munich's Bafta campaign, blamed the mistake on human error at the laboratory where the DVDs were encrypted. "Someone pushed the wrong button," she said. "It was a case of rotten bad luck." She insisted that the film's distributor, Universal, was not at fault.

The problem, it appears, was partly down to teething troubles with the limited edition DVD players issued last year to Bafta members. Developed by Cinea, a subsidiary of Dolby, the players permit their owners to view encrypted DVD "screeners", but prevent the creation of pirate copies. Munich screeners were encoded for region one, which allows them to be played in the US and Canada, rather than region two, which incorporates most of Europe.

The faulty DVDs only reached Bafta members on Saturday, which meant the film had already missed out on the first round of voting on January 4. In a further twist to the tale, a previous batch mailed out before Christmas were reportedly held up by customs officials in the UK. "It's been quite a cock-up," said one Bafta member, who spoke on condition of anonymity.

"We were promised that they were going to send screeners before Christmas, but they never arrived. Now we finally have a copy but there is no way we can watch it.

"The general feeling among members is that the film has now been shut out of the nominations simply because not enough people have actually had the opportunity to see the thing."

Having organised several London preview screenings of Munich before Christmas, Premier PR hastily scheduled three more for this week.

"The trouble is that Bafta members are scattered all over the country," the Bafta voter said. "We're not all based in London."

As arguably Spielberg's most controversial film to date, Munich is a dramatisation of the 1972 Olympic hostage crisis that resulted in the death of 11 Israeli athletes. The plot follows a hit squad from the Israeli secret service, Mossad, on the trail of the Palestinian Black September group behind the kidnappings.

The film has been criticised by Israeli officials for what is perceived as Spielberg's sympathetic attitude towards the Palestinian cause, and for allegedly equating Mossad's actions with those of the terrorists. Reviews in the US have largely been positive.

DVD screeners remain a vexed issue for distributors concerned about the potential for piracy. But the evidence suggests that they play a vital role in raising a film's profile among award voters.

"There are over 5,000 Bafta members," Ms Keene explained. "With the best will in the world, they don't all come to the preview screenings. Unless you send them DVDs it is really hard to get a film nominated."

This point was brought home last year when the distributor Entertainment took the decision not to provide Bafta voters with screeners of Million Dollar Baby. Clint Eastwood's boxing drama failed to gain a single nomination at the 2005 awards. One month later it scooped the major honours at the Academy Awards.