It's no secret that Mariska Hargitay is one of the most beloved actors. She's been starring as Olivia Benson on Law & Order: SVU for over 25 years, and she continues to be just one of the best people behind the scenes, too.

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And while Mariska has been in all of our living rooms for decades, some might not realize that she's the daughter of Jayne Mansfield. Nicknamed Hollywood's "smartest dumb blonde," she was an actor best known for her role in Will Success Spoil Rock Hunter? on Broadway and in the film adaptation. She was also considered a sex symbol and one of the most talked about Hollywood stars of the 1950s and early 1960s.

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Sadly, Jayne died in 1967 at the age of 34 when she was involved in a car crash in Mississippi alongside her attorney and then-partner, Sam Brody, a 19-year-old driver, and three of her children. Jayne, Sam, and the driver died at the scene, but her children, including Mariska, who was only 3 years old, survived.

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Mariska's brother, Zoltan, who was 6 years old at the time of the accident, recently revealed that after he was extracted from the car and on the way to the hospital, he noticed that Mariska wasn't with them. She was lodged under the passenger seat of the car and wasn't found right away.

Now, 58 years after her sudden death, Mariska decided to really explore who her mother truly was with the HBO documentary My Mom Jayne. The film depicts Jayne's quick rise to fame and her romantic relationships, which were the center of Hollywood gossip back then.

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Most notably, Jayne was married to Mickey Hargitay, a Mr. Universe winner and bodybuilder. The duo got married in 1958 and had three children together: Mickey Jr., Zoltan, and Mariska, with Mariska being born shortly after they decided to get divorced.

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Jayne also had two children from other relationships. Her oldest, Jayne Marie, was with Paul Mansfield, with Jayne notably having her when she was only 17. 

Following her divorce from Mickey in 1964, Jayne married Matt Cimber, with whom they share one son, Tony, born in 1965.

"Mickey was the most positive influence in her life, and even though he might've felt a lot of pain, he loved her. He always loved her. Even after they were divorced," Ellen Siano, Mickey's second wife and Mariska's stepmom, explained in My Mom Jayne. "She did come back to Mickey many times after that. They were together again for a few months around the time Jayne was pregnant with [Mariska]."

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Mariska added, "By the time I came along, I think there was a lot going on. And so there's a sense to me in some of the photos, it just seems like she wasn't holding me a lot. Like, she was off doing something else, and I just had to handle it. So I don't know if I had that attachment time with her."

Following Jayne's death, Mickey Jr., Zoltan, and Mariska lived with Mickey and Ellen, with Mariska describing it as, "the best times" and her earliest memories from childhood.

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And then, this is where My Mom Jayne dives into something that has not been publicly confirmed or discussed until right now. The fact that Mariska was not Mickey's biological daughter.

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"One time, when I was 12, I was [with my grandmother, Jayne's mother] and I was talking about my dad so reverently like I always did, and she looked at me with the strangest expression and said, 'I'm all you have.' And I knew it meant something, but I didn't know what," Mariska says in the documentary.

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Mariska explains that when she was 21 years old, she was invited to a fan event by the head of the Jayne Mansfield fan club. She attended, and then a few years later, when she was 25, she was invited to hang out with the head of the fan club again, where he asked her, "Do you want to see a picture of Nelson?"

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"I said, 'Who's Nelson?' and that's when I think the blood just drained out of his face and he sort of went white as a ghost and he looked at me, panicked, and he said, 'Well, it's probably not true,'" Mariska recalled. "He went around the corner and he pulled out this book and opened the page and he showed it to me, and I just, like, couldn't believe what I was seeing because it looked like the male version of me."

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"Life as I knew it was irrevocably changed," she added.

Mariska explained that she confronted Mickey, asking why he lied to her, and he got "more upset" than Mariska was. "I was in so much pain, but I could see his pain was almost worse," she said. "So, I decided I wouldn't talk about it again and I would never bring it up to him again, and I never did."

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Mickey died in 2006 at the age of 80.

Following this confrontation, Mariska said she had an identity crisis, adding, "I mean, who was I related to? Who did I belong to? And then, on top of it, I was born out of some affair, like some illegitimate, sinful mistake. I was so angry at my mother for leaving me in this mess, and for hurting my father, and for leaving me feeling so alone and untethered."

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She continued, saying, "So, for me to survive, I excised, disowned the part of myself that was my mother's daughter."

When Mariska was 30 years old, she attended Nelson Sardelli's concert in Atlantic City, and she confronted him afterwards. She said, "He looked at me and basically burst into tears, and he grabbed my ear, and he said, 'I've been waiting 30 years for this moment.'" Mariska added, "That was 30 years ago, and I've kept it a secret ever since."

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In 1974, Jayne's longtime friend and press agent, Raymond Strait, published a biography about Jayne where he alleged that Nelson was Mariska's biological father. But Mariska had never read the book, at the behest of Mickey, who told her to not read any books about her mother.

In My Mom Jayne, Mariska interviews Raymond, who said he thought it was his right to tell the story of Mariska's biological father, and he didn't think about how it would impact her family.

While performing in Atlanta in 1963, Nelson met Jayne in a club. Afterwards, Nelson said they went "every place together" and began performing together. He was even introduced to her children and attended her divorce proceedings from Mickey, with it being reported that Nelson and Jayne, "Hope to marry in the near future."

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They spent months traveling Europe together, where Nelson and Jayne learned that she was pregnant. However, they decided to part ways, with Jayne unable to make up her mind about whether to stay with Nelson or go back to Mickey, who she also loved.

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"I say this with the biggest shame of my life, I was wrong," Nelson tells Mariska in My Mom Jayne. He also said he and Jayne never spoke again.

"I can't imagine what your father felt, but I am grateful to him," he added.

Speaking about why he never tried to contact Mariska following Jayne's death, Nelson tearfully explained, "Your grandmother Vera wanted me to rock the boat and claim you or something. But by that time, Mickey was the father you knew. And your siblings, they were your siblings. What would I be accomplishing that would be beneficial to you? And as the years went by, I had a chance to talk to Mickey Hargitay one time, and he said to me, 'Nelson, nobody has to tell me who is the father of my child.' And I said to him, 'I will not embarrass you in any way. Never.'"

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Mariska's half sisters, Giovanna and Pietra Sardelli, recalled that Nelson and their mother made the decision to "stay quiet" and not reveal Mariska's true parentage, with Nelson telling them, "This little girl has a father who loves her like I love you. This little girl is safe. And if she's okay, she has just lost her mother, you cannot take away the only family she knows."

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Giovanna also shared that Nelson kept a locked drawer in his desk, which contained a letter from Vera talking about Mariska, and she opened it one day, and discovered that she had a sister she didn't know about.

They kept the secret for so long as a family that Giovanna even remembered meeting Katie Couric at a birthday party for Mariska years later, and when Katie asked how she was related to Mariska, she said that they were just family friends.

"My need was so big. My need for this, to honor Mickey, was so huge. But the fact is, I was wrong. Because you guys had to live all these years with this secret, and you were so generous, so generous to me. So, thank you," Mariska tells her two sisters in the documentary.

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The whole documentary is honestly a beautiful love letter to Jayne Mansfield, and it's astonishing watching Mariska connect with her mother and accept things about her life.

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You can watch My Mom Jayne on HBO Max now.

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