Emilia Clarke attends the premiere of "Last Christmas" at AMC Lincoln Square on Tuesday, Oct. 29, 2019, in New York. Picture: AP
"Game of Thrones" actress Emilia Clarke says Conleth Hill was behind the coffee cup howler during the show's final season, and insisted he confessed all to her during a boozy Emmys pre-party.

The 33-year-old actress was caught in the middle of some drama during the HBO fantasy epic's final season earlier this year when a Starbucks cup was spotted on screen in what was an embarrassing mishap for the show, and now she has revealed the culprit was actually one of her co-stars.

Appearing on "The Tonight Show with Jimmy Fallon" , she said: "So here's the truth. We had a party before the Emmys, and Conleth, who plays Varys - who was sitting next to me in that scene - he pulls me aside and he's like, 'Emilia, I have got to tell you something, love. The coffee cup was mine'.

"It was his! It was Conleth's coffee cup! He said so. He said, 'I think it was, I am sorry, darling. I didn't want to say anything because it seemed the heat was very much on you,' and I was like, 'What!?!'"

People are still talking about the awkward moment six months after the episode in question - 'The Last of the Starks' - aired, and Emilia is adamant Conleth was behind it, even if she admitted he had been drinking the night he confessed.

She added: "I think that's who did it, yeah. I mean, he said it. He might have been drunk, but he said it."

Meanwhile, Emilia revealed this week she's hopeful the cancelled "Game of Thrones" spin-off featuring Naomi Watts could still be "reincarnated" one day.

She said: "I'm not really too sure [what happened]. It's difficult to get stuff made. I wonder. Maybe it'll be reincarnated at some point, but if it wasn't meant to happen now, then I'm sure it's because they know that it wasn't going to be as perfect as it should have been."

The planned spin-off project was set to take place thousands of years prior to the events of the original series - which was based on George R.R. Martin's 'A Song of Ice and Fire' book series - but after filming the pilot episode, it has now been axed by HBO.

However, HBO has since confirmed plans for "House of the Dragon" - based on companion book "Fire & Blood" - which has been ordered straight-to-series, and will be set 300 years before the events of the fantasy epic.