In an interview with The Hollywood Reporter , Engelhardt said that she first met Allen at the Manhattan restaurant Elaine's when she passed him a note with her number. He invited her to his apartment on Manhattan's Upper East Side, she said, and the two began a "physically intimate" relationship even though she told him she was in high school. The age of consent in New York state is 17.
The Hollywood Reporter said two of Engelhardt's close friends corroborated her account. A representative for Allen didn't immediately respond to INSIDER's request for comment.
The two continued seeing each other in secret on more than 100 occasions, according to Engelhardt. The relationship, she said, inspired Allen's 1979 film "Manhattan," where a character played by Allen has a secret relationship with an underage girl.
"['Manhattan'] reminded me why I thought he was so interesting his wit is magnetic," Engelhardt said. "It was why I liked him and why I'm still impressed with him as an artist. How he played with characters in his movies, and how he played with me."
"I felt sick. I didn't want to be there at all, and yet I couldn't find the courage to get up and leave," Engelhardt wrote in an unpublished memoir viewed by The Hollywood Reporter. "To leave would mean an end to all of this. Looking back now, that's exactly what I needed, but back then, the idea of not having Woody in my life at all terrified me."
Engelhardt said she and Farrow ultimately became closer, smoking joints and bonding over animals and astrology.
"There were times the three of us were together, and it was actually great fun," she wrote in her memoir. "We enjoyed each other when we were in the moment. She was beautiful and sweet, he was charming and alluring, and I was sexy and becoming more and more sophisticated in this game.
But later, she felt manipulated.
"It wasn't until after it was done when I really had time to think of how twisted it was when we were together," she wrote. "While we were together, the whole thing was a game that was being operated solely by Woody so we never quite knew where we stood."
A representative for Farrow didn't immediately respond to INSIDER's request for comment.
Engelhardt said she's written two unpublished memoirs: One about her time with Allen, and the other about her time with Fellini.
She said she's speaking out now because she wants to add nuance to the discussion around Allen, who's become a target in the #MeToo movement because of his reported relationships with younger women and alleged sexual assault of his daughter Dylan Farrow when she was seven years old (a judge later found the allegations inconclusive.)
"What made me speak is I thought I could provide a perspective," Engelhardt told the Hollywood Reporter. "I'm not attacking Woody... This is not 'bring down this man.' I'm talking about my love story. This made me who I am. I have no regrets."
Read the full Hollywood Reporter story here.