My Mom Jayne,' which marks Mariska Hargitay's feature film directorial debut, premiered at the Cannes Film Festival. In the documentary, the actress reveals a shocking family secret she's kept for more than 30 years.

Mariska Hargitay is blowing the lid off a family secret that she’s been holding onto for decades and makes the big reveal in a new documentary focused on her bombshell mother, the late-actress Jayne Mansfield.

It was like the floor fell out from underneath me,' Hargitay says in the new film, her feature directorial debut.