Griffin described his father as a "narcissist" and a "vulture presiding over a carcass" and confirmed that the father of four had been hitting on his own daughter Tatum at Farrah's funeral.
Ryan O'Neal habitually cheated on Farrah Fawcett and contributed to her only child's crippling drug addiction by allowing him to use drugs at home, the actor's estranged son charged.
In an interview on CNN's "Larry King Live," O'Neal's son Griffin said his father -- whom he refers to as "Ryan" -- was once caught by Farrah in the act when he was with another woman.
"She walked in on him and he was with some other woman," Griffin O'Neal said in an interview that aired Monday."He locked every lock in the house, except he forgot that she had a remote control for the garage, and there she is."
Griffin, who has described his father as a "narcissist" and a "vulture presiding over a carcass," also confirmed what the father of four had already confessed: O'Neal had been hitting on his own daughter Tatum at Farrah's funeral.
"He was flirting with everybody," he said. "It was his daughter. He didn't realize it was her."
Griffin said that his father enabled Redmond -- who is now in jail on a probation violation stemming from a drug sentence -- by supplying him with cash and drugs.
"My dad just let him do whatever he wanted to do, supplied him with cash for his drugs, supplied him with everything," he said. "It was a losing battle."
When Griffin attempted to confront his father, he claimed O'Neal threatened to shoot him.
"My dad is a very, very, very violent man," he said.
Griffin was banned by his father from attending Farrah's funeral. Ryan later laced into his son just weeks after the funeral ceremony in an interview with Vanity Fair for its latest issue.
"I hate him!" O'Neal fumed about Griffin.
O'Neal fathered Tatum, 45, and Griffin, 44, with first wife Joanna Moore. He had son Patrick, 42, with actress Leigh Taylor-Young and Redmond, 24, with Farrah.
He said he has "never been happier" now that he talks only to Redmond.
Griffin also said alleged pal Alana Stewart, who appeared in the NBC documentary that chronicled Farrah's 2-1/2 year battle with cancer, wasn't trustworthy and that he was "disgusted" by her and others who exploited the star.
"She was selling Farrah's stuff on eBay the day Farrah died," he said.
Farrah died on June 25 after a long battle with anal cancer.