Sienna and Rhys arrive at red carpet separately, but can't stay apart for long

Miller, who wore her hair up, a black Alexander McQueen dress, platform shoes and Chanel jewellery, posed outside the cinema for photographers on her own.

Meanwhile, Ifans made his way into the cinema, nodding to journalists who shouted over questions.

Afterwards, the party-loving pair reunited at London bar View Lounge before heading home together.

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The actress has previously said that Ifans has been simply sleeping on her couch, but recent pictures of the pair kissing in public made it clear they're an item.

Miller co-stars in the film alongside Steve Buscemi, who is also the director.

The film centres around a confrontation between a world weary self-destructive journalist named Pierre and a famous soap star, Katya.

He is angered at being assigned to write a lightweight piece, while she is annoyed by his dismissal of her.

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Miller stopped briefly to talk to journalists inside the cinema, but didn't address her relationship with Ifans.

She was asked what it was like to be hassled by reporters and replied: "Really challenging," before making her way in.

Buscemi told reporters that Miller was "the only choice" for the role and was "really committed".

Asked jokingly if he thought he could be a fitting replacement for Jeremy Paxman he said he was not aware of the tough talking BBC interviewer's work.

Buscemi said he had been inspired by the original version of the film.

"I just really loved the character and the performances in the original," he said.

"The movie is not so much about an interview but two people from seemingly different worlds who come together and make a connection and then sabotage that connection."

The event was also attended by comedian Billy Connolly and singer Chrissie Hynde.

The film is released in the UK on November 9th.