Actress Mariska Hargitay released a family secret bombshell in a new interview.

For years, it was publicly believed that Hargitay's father was Mickey Hargitay, described by Vanity Fairas "a Hungarian bodybuilding champion turned actor who married Mansfield in 1956." Her mother, of course, was the Hollywood bombshell Jayne Mansfield.

According to Vanity Fair, Mansfield had a "well-publicized romance with an Italian entertainer named Nelson Sardelli," but then got back together with Mickey Hargitay before Mariska Hargitay was born.

When she saw a photo of Sardelli in her 20s, Hargitay "immediately knew in her bones that he was her biological father," Vanity Fair reported.

"It was like the floor fell out from underneath me," she said, according to Vanity Fair. "Like my infrastructure dissolved."

Mickey Hargitay denied it at first, Vanity Fair reported. At age 30, Mariska met Sardelli after watching him perform, thinking, "I've been waiting 30 years for this moment."

She says she told him, "I don't want anything, I don't need anything from you.... I have a dad."

However, she "gradually forged a bond with Sardelli and his daughters," Vanity Fair reported.

According to Norm Vegas, Sardelli has been in the U.S. since 1965, "arriving almost a decade after immigrating from Brazil. His Italian parents moved there in the early 1920s, looking for a better life." He forged a career acting, doing stand-up comedy, and singing, the blog says.

"I came to the United States in 1956, to Pontiac, Michigan, because in Brazil I worked for General Motors, but they were laying off people all over Michigan," he said to the blog.

Sardelli is still alive and participated in the documentary,People reported.

Hargitay came to realize that being raised by Mickey was best for her, and the documentary reflects this, Vanity Fair reported.

"I grew up where I was supposed to, and I do know that everyone made the best choice for me," she told Vanity Fair. "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."

Mariska Hargitay also opened up about the crash that killed her mom, Jayne Mansfield, while Hargitay was in the car.

"I don't remember the accident. I don't even remember being told that my mother had died," Hargitay told Vanity Fair.

The magazine explained that Hargitay harbored a "dark secret about her paternity that she'd been guarding for decades."

She is now directing an upcoming documentary about her mom called My Mom Jayne.

Hargitay remained close to Mickey Hargitay.

"He was my everything, my idol. He loved me so much, and I knew it," she told Vanity Fair. "I also knew something else-I just didn't know what I knew."