Claudia Winkleman has said Richard E Grant was so “giddy” at being made a traitor that he could not contain his excitement when he told his fellow players the news.

The veteran actor left the Celebrity Traitors stars shocked when he blabbed in the show’s opening episode, just minutes after the first roundtable, leaving many to believe it could not possibly be true.

In the debut episode of the second series, Winkleman appointed Grant and TV presenter Maya Jama traitors, after both had said they passionately wanted to take on the treacherous task.

During a conversation in the bar shortly afterwards, Grant was asked if he was a faithful or a traitor.

Grant replied with glee: “Traitor!”

Many of his fellow contestants laughed off his declaration, thinking he was joking or bluffing.

Winkleman said: “He was just so happy, he just couldn’t believe it.

“We go into a room after I’ve interviewed them all, and they say, ‘This is what I want to be’. You just couldn’t not give it to him. You couldn’t not, because he wanted it so much, and he was compelling.

“And he’s Richard E Grant, I couldn’t believe that he was actually in the castle.

“He was giddy and about five minutes later, he went ‘Oh!’.

“The genius of the game is everybody plays it completely differently, and he took that to the next level.”

Comedian Ed Gamble, who hosts spin-off show Uncloaked, said: “It was absolutely incredible. He was just vibrating with excitement in the turret as well.

“It felt like he’d just been given the lead role in a film, and he just had to tell everyone. Such an insane moment to start a brilliant series.”

Asked how she reacted when she watched the drama unfold in real time, executive producer Sarah Fay said: “It was a mixture of a little bit of sick coming up in my mouth and an air punch at the same time.

“We’ve never had anything like that happen before. Within five minutes of being out of the round table, he’s already mucked up. I still can’t believe it now.

“I mean, Richard E Grant, how iconic.”

She added: “Never in our wildest dreams did we think that we’d have a traitor admit they are a traitor five minutes after the round table.”

She continued: “It’s also just testament to the game that someone can actively say ‘I am a traitor’ and you still then doubt yourself and say ‘Oh no, surely he’s mucking around?’.

“He said ‘I am a traitor’ and lots of them were like ‘No, he’s just playing a game’. Come on guys.”

Celebrity Traitors continues on BBC One on Friday at 8pm.