He has been nominated for a Golden Globe for his lead role in Steve McQueen’s Oscar-tipped 12 Years A Slave, but Chiwetel Ejiofor was reportedly "hesitant" about taking on the part.
The British actor, 36, plays black New Yorker Solomon Northup who is kidnapped and sold into the American South slave trade in 1841.
But while many would jump at the chance, Ejiofor told the BBC that he needed "a moment to work out" whether to accept or decline the offer.
"When I read the script, I thought it was an extraordinary story but I did feel the weight and the responsibility of it," he said. "I didn’t want to be the guy that messed it up."
"I hadn’t seen a story from inside the slave experience as a film and I’d been accustomed to the fact I’d probably never see it," Ejiofor continued.
"So to be handed that kind of opportunity and the responsibility of telling (Northup's) story – I just questioned myself and was stuck for a moment with the questions of whether I could do that.
"Is there somebody else who has more access to this than you do? Can you get to all the places you need to get to in order to play this role and satisfy it?
"Is it going to be something that looking back on it you're proud of, or embarrassed, or worried by? My head was filled with all those questions," he said.
Perhaps Ejiofor's self-doubt will be eased when the Academy Award nominations are announced later this month – the Dirty Pretty Things star is widely-tipped to receive a nod.
Due for UK release on 10 January, 12 Years A Slave is adapted from Northup’s memoir describing life working on Louisiana plantations for 12 harrowing years.
Michael Fassbender stars as a brutal plantation owner while Brad Pitt, who is also one of the film's producers, appears in a minor role as a Canadian abolitionist who befriends Northup.
Ejiofor commented on the haunting history of black slavery, saying that filming felt like "dancing with ghosts…present right in the soil".
"There are some places that have a rich investment in what happened there, then there’s other places that seem very removed, almost as if it never happened," he said.
Director Steve McQueen has criticised Hollywood for a lack of movies addressing slavery when there are "hundreds and hundreds of films about the second world war and Holocaust".
Speaking to Sky News he said: "Slavery lasted 400 years and there are less than 20 (films). We have to redress that balance and look at that time in history."
Last month, Italian poster distributors sparked outrage when they printed unauthorised promotional material that highlighted the white actors in 12 Years A Slave above black lead Ejiofor.
The posters were withdrawn after a message on a blog called Carefree Black Girl read: "I don't remember Brad Pitt being the protagonist of the film or having such a pivotal role in the story to stay in the middle of the poster.
"I don't know anything about marketing strategy to appeal to audiences but isn't this going too far?"