Chynna Phillips Believes Mackenzie Phillips Had Sex with Father for 10 Years

(AP Photo)
Photo: Chynna Phillips, left, and her mother Michelle Phillips.

NEW YORK (CBS/AP) Chynna Phillips, half-sister of actress Mackenzie Phillips, said she believes Mackenzie had sex with her own father The Mamas and the Papas star John Phillips.

Photos: Mackenzie Phillips Sex with Dad

"I mean, who in their right mind would make such a claim if it wasn't true?" she told US Weekly of the claim Mackenzie Phillips made in her new memoir "High on Arrival."

Mackenzie Phillips, who details a decade of drug-clouded consensual sex with her father, told "The Oprah Winfrey Show" in an interview that aired Wednesday that her siblings "definitely have a problem with this."

Winfrey also read a statement from Genevieve Waite, John Phillips' wife at the time of the alleged affair and Mackenzie's stepmother that said John was "incapable, no matter how drunk or drugged he was, of having such a relationship with his own child."

Chynna Phillips, 41, of the 1990s group Wilson Phillips, told US Weekly that she received a call from Mackenzie Phillips, 49, in 1997 — over a decade after the affair ended — while she was waiting for a flight in New York City.

"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 said her half-sister told her. "And she went on to tell me that she had had an incestuous relationship with our dad for about 10 years."

Upon hearing the news, Chynna told Us Weekly that she went into "a deep, deep sadness and depression for about ten days. A part of me died when I found out."

Read more of "High on Arrival" here.>

September 20, 2009 - Mackenzie Phillips and John Phillips: Incest and Drugs Bombshell