Proof actress Gwyneth Paltrow missed the Venice festival because of a technical problem on the plane, which was forced to turn around and return to New York, festival organizers said.

Paltrow called the organizers in the news conference and said she was "heartbroken" not to be there. "I had an extraordinarily unpleasant evening last night trying to get there."

'I had all kinds of plane problems ... but I was very, very sorry not to be with you. It was going to be the highlight of my summer.'

The movie was instead promoted by her co-start, Anthony Hopkins and Jake Gyllenhaal. Hopkins has said Gwyneth Paltrow ranks alongside Jodie Foster as "spectacular" and "the most brilliant actress I have ever worked with".

"I've worked with two great actresses - Jodie Foster and Gwyneth Paltrow," he told journalists.

'Proof' is in the running for the Golden Lion, the Venice Film Festival`s top honor, the BBC reported.