Mackenzie Phillips' best friend released a statement to "Extra" on Friday, backing-up Mackenzie's claim of an incestuous relationship with her father, John Phillips of The Mamas & the Papas.
Owen Elliot, 42, is the daughter of Mama Cass Elliot of the The Mamas & the Papas. She tells "Extra," "Mackenzie is my best friend. She speaks her truth, and it's not a pretty truth. She has lived with this for 30+ years, and talking about this now is an important part of her recovery. I am very proud of her. Her bravery in telling her story is bound to help others."
15 Facts about Mackenzie Phillips
Mackenzie's birth name is Laura Mackenzie Phillips.
Mackenzie was born November 10, 1959 in Alexandria, Virginia.
Mackenzie Phillips was first known for her role in the 1973 hit movie "American Graffiti." She began filming at age 12; she was 14 by the time it was released.
Mackenzie became a star on the 1975 sitcom "One Day at a Time," co-starring Valerie Bertinelli. As the highest paid actress on the show, Mackenzie was reportedly commanding $47,500 a week.
She says her father John shot her up with heroin for the first time.
Her drug use caused her to be fired from "One Day at a Time" in 1980. She went to rehab that year -- with her father.
Mackenzie is the half sister of Bijou Phillips, Chynna Phillips and Tamerlane Phillips.
Chynna Phillips was a member of Wilson Phillips, with Wendy Wilson and Carnie Wilson.
In September 2009, Phillips revealed to Oprah that her father, John Phillips of the '60s band the Mamas and the Papas, raped her.
John Phillips (pictured on the left with Mama Cass Elliot and Denny Doherty) and his recording partner Scott MacKenzie co-wrote the 1960s hit "San Francisco (Be Sure to Wear Some Flowers in Your Hair)."
They also co-wrote the big 1980s hit "Kokomo" for The Beach Boys.
Mackenzie was named after Scott MacKenzie.
Phillips said her father raped her in 1979 on the eve of her wedding to Jeff Sessler, a member of the Rolling Stones entourage. She and Sessler divorced in 1981.
She sang in her father's music group, The Mamas and the Papas, when the group made a comeback in the 1980s. It is during this time that she claims their sexual relationship was consensual.
In her book, "High on Arrival," Mackenzie claims her father wanted to run away with her.
"One night Dad said, 'We could just run away to a country where no one would look down on us. There are countries where this is an accepted practice. Maybe Fiji."
John Phillips died in 2001 of a heart attack at age 65.
Mackenzie returned to TV in the late 1990s, starring in the Disney Channel series "So Weird" as a veteran rock musician juggling motherhood and a career comeback.
Mackenzie is the sister-in-law of Billy Baldwin. Billy is married to her half-sister, Chynna Phillips.
In August 2008, Mackenzie was arrested at Los Angeles International Airport with drugs hidden in balloons and plastic bags. She pleaded guilty to cocaine possession and was sent back to rehab.
