However, it's since been reported that Elba is playing an entirely different character, although who it might be has not yet been revealed.
"James Gunn is an incredible director to work with, and the actors are amazing," Elba marveled. "So I'm having a great time."
The Suicide Squad tells the story of a group of imprisoned supervillains who are given the chance at redemption by becoming anti-heros as part of a band of crime fighters seeking clemency. Elba also played the super-powered villain in the recent high-octane blockbuster Hobbs & Shaw, and plays the baddie in Cats, starring as Macavity the Mystery Cat.
"Bad guys are just written better," Elba said of his appreciation for playing villains. "They're just less boring, they get to say all the stuff that's in their head, and then you get to do it with charisma."
"But, you know, this guy, he's not so much as bad, he's just desperate. Macavity has one life left out of all his nine, and he's desperate," Elba explained. "So, you know, [director] Tom Hooper and I, we wanted to bring that out. So he's not just like a bad guy, he's a desperate guy."
For Elba, stepping into a role like Cats is a notable departure from the roles that he's become most famous for -- including the hardened homicide detective in the TV series Luther or the Norse god Heimdall in Marvel Cinematic Universe -- and that's one of the main reasons he signed on.
"I've never done a musical on film. I'm one of these actors that like to do as many different things as I can," Elba shared. "I think that's part of the job… I just wanted to challenge myself and try something different."