Cinemas in the UK and US are getting ready for their busiest day of the year as the new Harry Potter film opens to sell-out audiences.

The Chamber of Secrets will show on more than 1,000 screens in the UK alone - two-fifths of the country's movie capacity.

In Britain, the film has already raked in nearly �8m in previews ahead of its general release date on Friday.

It took three days to gross �7,861,704 from 522 sites - taking more than the top 15 films in the British Isles put together.

Daniel Radcliffe's Potter will make millions for Warners

British cinemas have taken delivery of 1,263 prints of the film - about 40% of UK screens, according to trade magazine Screen International.

The UK's Odeon chain has sold nearly 350,000 advance tickets worth �1.7m.

It is reserving 228 screens for Potter - almost half its UK total - and will do so until demand wanes.

"It's been incredible," said an Odeon spokesman.

"We've tripled our call centre staff to meet demand and opened a dedicated Harry Potter film line.

It's certainly matched the demand of last year's film

Odeon spokesman

"We've had hundreds of e-mails from fans wanting to know details of the film and when tickets go on sale.

"It's certainly matched the demand of last year's film."

The first Potter adventure, The Philosopher's Stone, took �64.3m in the UK after it opened a year ago.

Worldwide it made $961m (�618m) to become the second highest grossing movie of all time behind Titanic.

Warner Bros, which is producing the Potter films, said it could not comment on box-office expectations for The Chamber of Secrets.

But there is little doubt that the film will follow the success of its predecessor and take millions worldwide.

But days before the film appears on cinema screens around the world, it has appeared on the internet.

Warner Bros., the film's distributors, have confirmed that illegal copies of the film have appeared on sites that show copies of new movies.

It is thought the pirate copies are taken from handheld video cameras smuggled into preview screenings.

The film's general release comes as veteran British actor/director Sir Richard Attenborough denied rumours he was to replace the late Richard Harris as wizard Dumbledore in the third film.

The 79-year old said at the launch of cinema in Edinburgh his schedule was too busy to allow him to shoot the third of the Potter adaptations.

Meanwhile, a precher in Portland, Maine, has told parishioners that JK Rowling's books promote paganism, and has ripped them up at his services.

Reverend Douglas Taylor's group, The Jesus Party, have ripped up books in the lead-up to the new movie. The first Potter movie was a massive hit in every significant global territory, including Europe, Japan, the Americas and Australia.