Mariska Hargitay just dropped a massive family bombshell that’s been buried for over 30 years, one that rewrites the narrative of her famous Hollywood upbringing.

The “Law & Order: SVU” star stunned fans at the Cannes Film Festival with the premiere of her new documentary “My Mom Jayne,” a deeply personal tribute to her late mother, screen siren Jayne Mansfield.

But in the process of honoring her mom, Mariska Hargitay revealed something no one saw coming: the man who raised her, bodybuilder Mickey Hargitay, is not her biological father.

The jaw-dropping reveal marks Hargitay’s feature film directorial debut, and the documentary doesn’t hold back.

Alongside the tragic story of her mother’s death in a horrific car crash in 1967, when Mariska was just three years old, comes the revelation that her real father is former Las Vegas entertainer Nelson Sardelli.

According to her interview with Vanity Fair, the truth came out when she was 25 years old. She confronted Mickey, who insisted he was her father, and they never spoke of it again. But the questions lingered. She wondered why she didn’t quite feel like she shared the same Hungarian roots as her brothers Zoltan and Mickey Jr.

When she turned 30, she finally met Sardelli in Atlantic City, where he was performing.

Hargitay told Vanity Fair that she introduced herself to him as his daughter. His emotional reaction? “I’ve been waiting 30 years for this moment.” But she wasn’t ready to jump into a father-daughter reunion.

“I don’t want anything. I don’t need anything from you… I have a dad,” she reportedly told him, channeling her signature SVU intensity. “There was something about loyalty. I wanted to be loyal to Mickey.”

The emotional complexity of discovering a hidden side of her family weighed heavily.

“Knowing I’m living a lie my entire life,” she admitted, became a painful truth to face. Sardelli, now in his late 80s, appears in the documentary along with his two daughters, Mariska’s half-sisters.

Eventually, Hargitay found peace and came to understand why her mother, Jayne Mansfield, returned to Mickey Hargitay. It was to provide stability.

Before the Cannes premiere, she held a private screening in Las Vegas for her newfound siblings, and their reaction left her shaken.

“They just wept and wept and wept. These two women that I love so much. I made them secrets!” she said. “It’s so heartbreaking to me.”

Now 61, Hargitay says she finally felt ready to tell the truth. “I grew up where I was supposed to… I’m Mickey Hargitay’s daughter, that is not a lie.” She called the film a “love letter” to the man who raised her, adding, “there’s no one that I was closer to on this planet.”

She also opened up about her therapy sessions, where she would often drift off to sleep whenever conversations veered too close to painful memories… “like a narcoleptic!” she joked.

She initially chalked it up to exhaustion from the grueling hours of filming “Law & Order: SVU,” all while balancing life as a mother of three. But her therapist had another theory. The sudden sleepiness was likely a deeply ingrained defense mechanism, protecting her from confronting unresolved trauma.

To break through it, she’d need to face the shame tied to her sex symbol mother and finally confront the long-hidden truth about her biological father.

“My Mom Jayne” also reflects on her mother’s iconic status as a Golden Globe-winning actress and 1950s sex symbol, whose life ended tragically in a crash on June 29, 1967.

Jayne, her partner Sam Brody, and their driver were killed instantly when their car slammed into a tractor-trailer in Biloxi, Mississippi. Miraculously, Mariska and her two brothers, asleep in the backseat, survived with minor injuries.

Jayne left behind five children. Jayne Marie (from her first marriage to Paul Mansfield), Miklos, Zoltan, and Mariska (with Mickey Hargitay), and Antonio (with third husband Matt Cimber).

With “My Mom Jayne,” Hargitay not only honors a Hollywood legend but finally lifts the curtain on the family secret she’s held close for decades.