From Hollywood to Paul Hollywood? Keira Knightley tried to miss The Imitation Game premiere to watch Bake Off

The star was horrified when the BFI screening coincided with the popular cookery contest

Keira Knightley and Benedict Cumberbatch at the premiere of The Imitation Game at the BFI London Film Festival

Keira Knightley might have turned up to the premiere of her new movie The Imitation Game in a posh frock, but the actress revealed she tried to duck out of the occasion as she didn't want to miss the finale of The Great British Bake Off.

The screening of the Alan Turing biopic, in which she co-stars alongside Benedict Cumberbatch, at the opening night of the London Film Festival coincided with the climax of the cooking contest which was watched by more than 13 million viewers on BBC1.

Knightley revealed she tried to persuade her agent it would be fine to miss the screening to head home early and when that failed she had to content herself with leaving the party to watch it on catch-up shortly afterwards, taking precautions to avoid a spoiler about the winner.

"There was a real moment where I was like 'no, but no, you don't understand' and I did actually say to my agent 'is it alright because I have seen the film twice before and I love the film but can I just walk the red carpet and just go back and watch it?' Knightley explained, during an interview for Saturday's edition of The Jonathan Ross Show.

"I did actually leave the party a bit early so I could watch it on iPlayer afterwards so that nobody would tell me what happened. I turned off the radio on the way back so I didn't know."

Knightley also told how she struggles to understand the appeal of social media. She said she dabbled to see what the fuss was about but got "freaked out".

"I did actually join Twitter for about 12 hours because I tried to be down with the kids and it just creeped me out. I didn't post anything and I was under a false name and I think because Chloe followed me, suddenly all these people started following me and posting 'I'm having a cup of tea now' and I just got completely freaked out.

"I did the same thing with Facebook, I joined that for about an hour and that still tries to follow me."

Additional reporting by PA