Isla Fisher has opened up about her terrifying near-death stunt experience while filming Now You See Me.

The 48-year-old actress starred in the 2013 movie alongside a star-studded cast featuring Jesse Eisenberg, Mark Ruffalo, Morgan Freeman, Dave Franco, Michael Caine, and Woody Harrelson.

Isla Fisher starred in Now You See Me (2013). Credit: Gary Gershoff / Getty

Fisher took on the role of a magician named Henley Reeves – who was one of the Four Horsemen alongside Daniel Atlas (Eisenberg), Merritt McKinney (Harrelson), and Jack Wilder (Franco).

In the opening scene of the movie, the Four Horsemen wow the crowd with their mind-blowing tricks.

It begins with Daniel flaunting his card stunt, while Merritt is seen revealing his hypnotic abilities. Jack Wilder then performs an enchanting illusion with a spoon, before Henley makes her first appearance chained to the bottom of a tall water tank, with piranhas circling above her.

The escapologist tells the audience that she has just one minute to escape her shackles before the scary pirañas fall into the tank.

Watch the scene below:

In the frightening scene, Fisher’s character realizes that her chains are trapped between the grates at the bottom of the tank. So, it’s expected that she would appear distressed at this point.

However, the Wedding Crashers star didn’t have to act out this emotion, as she was really fearing for her life at that moment.

She started frantically banging on the walls of the tank to alert the crew, but they also thought that she was acting.

“They had a guy who was off camera, but he was a long way away with a can of oxygen. By the time I realized I couldn’t get up and beckoned for him, I realized that I had run out of air,” Fisher revealed, per Metro.

Isla Fisher revealed that she almost drowned during the tank scene. Credit: Ben Pruchnie / Getty

“Luckily, I managed to get free and stay level-headed and got out before it went even more horribly wrong,” she added.

In a separate interview, the Confessions of a Shopaholic star explained in a Rotten Tomatoes commentary uploaded to YouTube that she spent a whole two months preparing for the scene.

“I was just practicing holding my breath and getting comfortable with the handcuffs. It still didn’t stop me from being actually stuck underwater,” she said. “I couldn’t breathe or get up for air, which was a little hairy.”

Fisher said she experienced “white noise,” as she “couldn’t hear anyone,” in the tank, adding: “The adrenaline of being chained underwater meant that I had less oxygen in my lungs, I ran out of air quicker and panicked slightly more.”

Fisher starred alongside Mark Ruffalo and Jesse Eisenberg. Credit: Alberto E. Rodriguez / Getty

While life-threatening stunts are usually performed by highly-trained professionals, the mother-of-three chose to do this one herself.

Speaking to Cosmopolitan at the time of the film’s release, Fisher shared: “I don’t see myself as particularly brave. If something terrifies me, I am going to do it. The director [Louis Leterrier] said to me, ‘Wow. I’ve worked with so many actors on big action movies, and you’re the only one who’s done all their own stunts’.”

“I said, ‘I didn’t know I had a choice’. I thought you just had to get on with it. It’s the Australian way,” she concluded.