Kubrick: Experimented with a real robot

Kubrick came up with the idea 20 years ago, sketched it out in detail and suggested that Spielberg direct it.

Starring Jude Law and 13-year-old Sixth Sense star Haley Joel Osment, one journalist said it feels like what might happen if "cute little ET calls home and HAL the evil computer answers".

Spielberg, who was behind hits including ET, Schindler's List and Jurassic Park, took over the project when Kubrick died in 1999.

Film bosses are hoping its success will surpass that of Spielberg's last blockbuster, 1998's Saving Private Ryan, which made more than $216m (�153m) in America.

"That's where I think we could be with this movie, and if we're bigger I would be thrilled," Warner Brothers distribution president Dan Fellman told Variety magazine.

Kubrick's original plan was to use a real robot to play the film's robotic boy, who is programmed to love, it has been revealed.

But Spielberg gave that role to Osment.

Plastic skin

Kubrick did not want a child actor to show any signs of ageing during his notoriously long shoots.

Kubrick's brother-in-law and long-time producer Jan Harlan said: "Stanley would jokingly say, 'By the time I'm finished, the kid would have a beard'."

Jude Law plays robot lover Gigolo Joe

At one point, the pair experimented with an actual robot covered with plastic skin.

"The robot was lifeless - a total failure," Harlan said. "It really looked grotesque, and we gave up on it."

But after watching 1993's Jurassic Park, Kubrick realised Spielberg and his special effects could help.

In 1994, Kubrick asked Spielberg to direct the film, telling him: "I think this movie is closer to your sensibility than mine."

The pair had fax machines locked in secret rooms so they could send each other pages of the script without it being seen or leaked by anyone else.

'Unique'

But critics have been divided over the finished product.

Daily Variety's reviewer Todd McCarthy praised the movie, describing it as "the fruit of the unique spectral artistic convergence of two cinematic titans".

But New Yorker critic David Denby was not so kind. He wrote: "A deceased director rises from the crypt and drains the vitality out of a living one."

AI is widely expected to take the top American box office spot from The Fast and the Furious, a film about illegal street racing in Los Angeles.

Pootie Tang, starring comedian Chris Rock, Kirsten Dunst's Crazy/Beautiful and Baby Boy, starring Snoop Doggy Dogg, all also appear at US cinemas this week.