The 50-year-old Emmy Award winner, who portrays commander Amanda Waller in the new DC Comics superhero film, admits some scenes were so intense, she is surprised she survived the stressful filming process.

"Just put it this way, it got so crazy that there were times during filming that I had heart palpitations," Viola tells E! Live from the Red Carpet. "Not only heart palpitations, but at one point I said, 'Did I suffer from hearing loss? Why is my left ear still pounding?'"

Suicide Squad boasts an all-star lineup, with Jared Leto portraying villain The Joker, Margot Robbie depicting The Joker's diabolical love interest Harley Quinn, Will Smith as assassin Deadshot, Jai Courtney severing heads as Boomerang, and Cara Delevingne casting spells as June Moone, aka Enchantress.

Jared has previously grabbed headlines for his behind-the-scenes conduct on the set, embracing method acting throughout the shoot, and sending his castmates disturbing gifts such as used condoms, a dead pig, anal beads, rats and pornographic magazines, among other things - to keep up with his super evil The Joker character.

Although some people would be horrified by Jared's approach, Viola insists she and the rest of the cast were deeply inspired by his wicked antics.

"Jared Leto, Margot Robbie, I mean everyone, every single person in it gets to be completely insane because all the characters are insane," she shared. "They're bad guys. We're all bad guys. Amanda Waller is... a bad guy, bad girl. We're not nice."

Suicide Squad opens in U.S. theatres on 5 August (16).