Michael Sheen has said starring as Chris Tarrant in Quiz has given him a “real respect” for the TV host.
The Welsh star, 51, plays the presenter in the series based on the infamous Who Wants To Be A Millionaire? cheating scandal.
Quiz stars Matthew Macfadyen as Major Charles Ingram and Fleabag’s Sian Clifford as his wife Diana.
Sheen – who has famously played Tony Blair, Sir David Frost and Brian Clough – watched hours of tapes from the show as part of his research.
He said: “Watching him on the show – I always enjoyed the show and I always enjoyed him on the show – did give me a real respect for what a brilliant job he does on it.
“It’s not just him presenting it, he’s stage managing that thing. The way the music and lighting…
“But watching it over and over again and then actually doing it, it’s so amazing what the music and the lighting does.”
Sheen said he had watched episodes of Cash Mountain, a precursor to the programme that did not feature its dramatic lighting and music, and had found it less compelling.
He added: “The way Tarrant plays with that, he’s really good.
“It’s watching how he gets information – quite complicated information about the rules and where they’re at in the game, making sure the player knows how much they’ll lose if they play this…
“But they don’t have to play it. And he does all of it brilliantly, without feeling like it’s dragging.
“You can see that he really enjoys doing the phone a friend bit and I think that’s because of him doing radio shows – that’s the closest to doing a radio show and being able to talk to someone on the end of the phone.
“So it’s finding all that sort of stuff and watching it and watching it to get a sense of ‘What is he really doing here?’ so there’s a little bit more going on underneath.
“And realising how brilliant he is at doing it – it’s not a straightforward thing to just copy what he does.
“It takes real skill to do what he does, so you have to just get really familiar with what he does.”
Dubbed the “Coughing Major”, Ingram was found guilty along with his wife and their accomplice, Tecwen Whittock, played by Michael Jibson, of cheating their way to the top prize in 2001.
The trio maintained their innocence but were convicted of deception following a high-profile 2003 trial.
Quiz will begin on ITV on April 13.