Former child star Mackenzie Phillips said Wednesday (Spet. 23) that she maintained a sexual relationship with her father, John Phillips of acclaimed '60s vocal group The Mamas and the Papas, for more than a decade. According to a report in People magazine, Phillips, now 49, was 19 years old when she was raped by her father on the night before her wedding.

"I woke up that night from a blackout to find myself having sex with my own father," she writes in her memoir, "High On Arrival," which was released today.
 
In an interview that aired on the Oprah Winfrey Show Wednesday, Philips said the relationship became "consensual" and lasted for nearly a decade, until she became pregnant. Philips also told Winfrey that her father, who died in 2001, introduced her to drugs at the age of 11, teaching her how to roll joints and injecting her with cocaine. She has since been in and out of rehab, and was arrested for drug possession in 2008.
 
Phillips' family -- which includes former stepmother and Mamas and Papas member Michelle Phillips and half-sister Chynna Phillips of the 1990's trio Wilson Phillips -- had mixed reactions to the accusations.
 
In a conversation with Hollywood Reporter columnist Roger Friedman, Michelle Phillips said, "John was a bad parent, and a drug addict. But [expletive deleted] his daughter? If she thinks it's true, why isn't she with a good psychiatrist on a couch? I think it's unconscionable that Oprah would let her do her show. I have every reason to believe  it's untrue. Oprah should be more judicious about who she has on her show."
 
On the broadcast, Winfrey read a statement from Genevieve Waite, John Phillips' wife at the time of the alleged abuse and Mackenzie's stepmother that said he was "incapable, no matter how drunk or drugged  he was, of having such a relationship with his own child."
 
But Chynna supports her half-sister's version of events, and even claims to have known about the abuse since 1997 after a shocking phone call from Mackenzie.
 
"She said, 'I don't know why, but I just really felt the need to call you and tell you something that I think you need to know,'" Chynna told Us Weekly. "And she went on to tell me that she had had an incestuous relationship with our dad for about 10 years.
 
"Somebody could have dropped a piano on my head and I probably wouldn't have felt it," she continued. "But I knew it was true. I mean, who in their right mind would make such a claim if it wasn't true?"
 
Michelle and John Phillips were half of the Mamas and the Papas, along  with Cass Elliott and Denny Doherty. The group's songs included hits like "Calfornia Dreamin'," "Monday Monday," and "I Saw  Her Again Last Night." Mackenzie was born before the group formed in 1965.