Former Beastie Boy Adam Horovitz has come out swinging against his famous playwright father, Israel Horovitz, after his dad was accused by multiple women – including his son’s high school girlfriend -- of sexual misconduct, including rape and the forced fondling and kissing of women as young as 16.

“I believe the allegations against my father are true,” Adam Horovitz told The New York Times in a statement. “And I stand behind the women that made them.”

Nine women told the Times that Horovitz, who wrote over 70 plays including the Broadway hit “Who Parked Your Car in Harvard Yard,” made unwanted sexual advances against them. One woman, Jocelyn Meinhardt, was his son Adam’s ex-girlfriend. She said when she was 19 and working on a summer fellowship at the Gloucester Stage Company in Massachusetts, Horovitz drove her to his house, locked her in and raped her.

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A former babysitter, Frédérique Giffard, said she was 16 when Horovitz groped her breasts and put her hand on his penis. And just last year Horovitz grabbed the breasts of 21-year-old Maia Ermansons, she said.

“I felt close to him like a grandfather, but also he was a somewhat famous guy whose time I felt privileged to have,” Ermansons told the paper. “For the man who represented all that, to treat me the way he did, was the ultimate betrayal.”

“I believe the allegations against my father are true, and I stand behind the women that made them” — Adam Horowitz

Horovitz, 78, told The New York Times he has “a different memory of some of these events, I apologize with all my heart to any woman who has ever felt compromised by my actions, and to my family and friends who have put their trust in me. To hear that I have caused pain is profoundly upsetting, as is the idea that I might have crossed a line with anyone who considered me a mentor.”

This is not the first time Horovitz has been accused of sexual misconduct. In 1993 a story in the Boston Phoenix detailed the very similar allegations of 10 unnamed women accusing him of sexual assault and harassment while he was the artistic director of the Gloucester Stage Company. The Gloucester Stage board’s president, Barry Weiner, dismissed the accusations at the time.

The Gloucester theater fired him last week after some of the allegations to The Times were brought to their attention.

Many of the women Horovitz allegedly preyed on said they maintained complex relationships with him after the initial alleged attacks, and Meinhardt said she even had consensual sex with him twice more, “in that I didn’t say no clearly.”

Giffard said she confronted Horovitz in 2009. “I said, ‘I was 16 and he was 52, and that the whole thing was completely wrong,’” Giffard told The Times. “He said he hadn’t realized that he had harmed me. He weakly apologized.”