The pair have clearly developed a happy working relationship on the show, which features Miss Friel as Holly Golightly, the socialite who captures a young writer's heart - and includes a nude scene.

Cross and Miss Friel, who is the long-term partner of actor David Thewlis, 46, left the Theatre Royal together on Wednesday night and visited a number of bars before ending up at the Wolesley restaurant in Piccadilly.

A friend of the actress, who has a four-year-old daughter, Gracie, by Thewlis, said: 'Joe is a good friend of Anna and David. There is nothing more to it than that.'

The night after the restaurant cuddle, Miss Friel, Thewlis and Cross were seen sharing a taxi as they left the Berkeley Square Christmas Ball.

And on Saturday night after the show, the former Brookside actress and Cross went for a drink with friends at a bar in central London.

They were sharing a rolled-up cigarette in the street when Miss Friel broke off to give Cross a lingering kiss.

Miss Friel admitted she was 'tactile' in a recent interview to publicise her hit U.S. show Pushing Daisies, in which she stars with actor Lee Pace.

She said: 'It's not nice to work with someone as gorgeous as Lee and not to be able to give him a hug. I'm a tactile person and hugs are something I hold dear to my heart.'