Papas star 'slept with daughter'

Mackenzie Phillips, a former child TV star, alleges the incestuous liaison - disclosed in her recently published memoir - began in 1979 when she was 19.

Speaking on The Oprah Winfrey Show, she said the relationship was a "betrayal".

Phillips' claims have been disputed by Genevieve Waite, her father's wife at the time of the alleged abuse.

In a statement read out by Winfrey, she said John Phillips was "incapable, no matter how drunk or drugged he was, of having such a relationship with his own child."

Mackenzie Phillips starred in 1970s sitcom One Day at a Time and appeared in George Lucas's 1973 film American Graffiti.

The 49-year-old has a long history of drug abuse and was arrested for possession of cocaine and heroin last year.

'Abuse of power'

In her book, entitled High on Arrival, she alleges she first had sexual intercourse with her father on the night before she was to be married to a member of the Rolling Stones' entourage.

"I woke up that night from a blackout to find myself having sex with my own father," she writes.

Phillips describes those first sexual encounters as rape - but says the relationship later became consensual and ended when she fell pregnant. She was unsure who had fathered the child and claims to have had an abortion paid for by her father.

"I never let him touch me again," she told Winfrey, calling the alleged incest "an abuse of power".

But she said she forgave her father on his deathbed in 2001, describing him as "very tortured man".

John Phillips married four times, having Mackenzie - his oldest daughter - with his first wife Susan Adams.

He formed the Mamas and the Papas with his second wife Michelle, whom he divorced in 1970.

In a statement, Michelle Phillips said her stepdaughter's public disclosure was "an unfortunate circumstance" and "very hurtful for our entire family".

One of the most popular bands of the 1960s, the Mamas and the Papas are best known for their hits California Dreamin' and Monday, Monday.

Mackenzie Phillips' half-sister Chynna had pop success with 1990s group Wilson Phillips.