During a recent interview, the actress delved into a decades-long secret that shook her sense of identity and left her questioning everything she thought she knew.

In a candid new interview with Vanity Fair, Mariska Hargitay opened up about a long-buried family truth revealed in her upcoming documentary, “My Mom Jayne.” While she was raised as the daughter of Hollywood strongman Mickey Hargitay, the “Law & Order: Special Victims Unit” star shared that her biological father is actually Italian singer Nelson Sardelli.

Mariska explained that her mother, actress Jayne Mansfield, briefly split from Mickey in 1963 and had a high-profile romance with Nelson before reconciling with Mickey ahead of Mariska’s birth in 1964.

However, when Mariska was in her twenties, someone showed her a photo of the Italian singer, and she instantly knew he was her biological father. The actress recalled feeling like the floor had fallen out from under her.

Confronting Mickey yielded only denial and overwhelming emotions. Thus, Mariska never raised the subject again, and the man she had grown up believing to be her father passed away in 2006.

Eventually, in her 30s, the actress tracked down Nelson during one of his performances in Atlantic City. Though he burst into tears and told her he’d been waiting decades for that moment, she didn’t meet him with open arms.

Channeling her fierce on-screen alter ego, Olivia Benson, Mariska made it clear she wasn’t seeking anything more than the truth. “I was like, ‘I don’t want anything, I don’t need anything from you.… I have a dad.’ There was something about loyalty. I wanted to be loyal to Mickey,” she shared.

Still, the emotional weight of their conversation lingered. It stirred up years of inner conflict about where she came from and who she truly was. The meeting didn’t bring closure, at least not immediately.

Instead, it left her navigating a storm of personal reckoning — why she had always felt such ease during childhood trips to Italy, why certain pieces of her identity had always felt disjointed, and whether she was the product of love or of secrecy.

In time, though, she began to form a relationship with Nelson and his family. It wasn’t simple, but it brought her to a deeper understanding of her past and of the choices her mother made. Jayne, she came to believe, had returned to Mickey because she trusted him to provide the kind of loving, stable home that baby Mariska needed.

“I grew up where I was supposed to, and I do know that everyone made the best choice for me. I’m Mickey Hargitay’s daughter — that is not a lie. This documentary is kind of a love letter to him because there’s no one that I was closer to on this planet,” the actress stated, teary-eyed.

Long before his name resurfaced in headlines tied to Mariska’s past, Nelson was carving out a name of his own. Born in Brazil to Italian parents who had immigrated in the 1920s, he arrived in the United States in 1956, eventually settling in Pontiac, Michigan.

He started out in economic research at General Motors but quickly discovered his true calling wasn’t behind a desk or in a hospital, where one brush with a catheter sent him running for the stage.

Nelson’s big break came at a local tavern with a mic and a modest $27.50 gig. A few songs turned into regular bookings, and one day, a feature in a Brazilian sports publication dubbed him an “international entertainer.”

With natural showmanship and sharp wit, he evolved his act to include comedy, despite early setbacks, and eventually opened for legends like Judy Garland. His mix of music, stand-up, and theatrical flair became a hit in Vegas lounges and beyond.

Hollywood soon followed. He landed roles in films like “The Professionals” and “Myra Breckinridge,” where his Italian charm and comedic timing made him stand out.

Mae West herself handpicked him for the part, a moment he recalled with the animated humor that came to define his career. By the early 2000s, Nelson had worked stages from the Catskills to Atlantic City, joking that he became “the highest-paid unknown” — a title he wore with pride.

However, as he and Mariska formed a relationship and the actress found peace with her truth, a new challenge emerged — figuring out how to share it. Making “My Mom Jayne” wasn’t just a creative endeavor but a deeply personal act of healing. But convincing her family that it needed to be done wasn’t easy.

“There was a lot of hesitation,” she admitted. Some loved ones struggled to understand why she felt compelled to open old wounds in front of cameras. But over time, both sides of her extended family — the Hargitays and the Sardellis — not only came around but agreed to participate.

Nelson himself was the first to step up, laying bare his emotions for the documentary. Mariska’s Hargitay siblings — Jayne Marie, Zoltan, and Mickey Jr. — also offered raw, candid reflections that made it clear just how far-reaching the impact of silence and secrecy had been.

When they finally watched the completed film together in a Los Angeles screening room, they sat arm in arm. The actress described the moment as cathartic, saying it felt like decades of fragmented memories were finally being stitched into something whole — something they could finally face together.

Later, in Las Vegas, a private screening with her Sardelli sisters hit just as hard. They wept openly, and so did she. For years, Mariska had introduced them as “family friends,” shrinking them down to a footnote in her public life. “I’m not good with lies,” she admitted, tears welling. “This movie is also for them — a way to unburden us all.”

Now, after a journey that’s taken decades to complete, the “Law &Order: Special Victims Unit” star is preparing to bring “My Mom Jayne” to Cannes — the very place where her mother once lit up the red carpet.

For Mariska Hargitay, bringing her mother’s story back to the Croisette isn’t just symbolic — it’s deeply personal. “The fact that I get to take her back and tell her story there, I just don’t have the words,” she said, nearly trembling with anticipation.

As the premiere nears, she reflected on the long road to this moment — 30 years in the making. “It’s wild,” she said, eyes gleaming. “I feel like I’m seven.”