(NewsNation Now) — Forty years after Hollywood star Natalie Wood died in a mysterious manner aboard a yacht, her sister, Lana Wood, says she knows how it happened. 

Natalie Wood started acting young. She played the precocious Santa Claus skeptic in “Miracle on 34th Street” at just 8 years old. She went on to act in at least 28 films, including “West Side Story,” where she played the leading female role of Maria.

Wood would go on to win four Golden Globes and three Oscars before drowning at the age of 45 during a boat outing with her husband, Robert Wagner.

Her death remained under a cloud of mystery and Wagner was never charged in the case — even when police relabeled him as a person of interest in 2018.

Now, her sister Lana Wood claims in her book “Little Sister: My Investigation into the Mysterious Death of Natalie Wood,” that Wagner killed her sister in a drunken rage.

Natalie Wood’s body was found off Catalina Island in California. Authorities initially ruled the death an accidental drowning, but that has changed after years of scrutiny and more witnesses emerging.

According to Lana, Natalie and Wagner had been “bitterly” fighting the entire trip to Catalina.

In her book, Lana details an evening of rough weather aboard the ship, a meal Natalie shared with actor Christopher Walken and Wagner threatening Walken with a broken wine bottle. Wood then left the restaurant and returned to her room on the ship, according to Lana.

In another bombshell, Lana claims Natalie was sexually assaulted by actor Kirk Douglas.

“I remember that Natalie looked especially beautiful when Mom and I dropped her off that night at the Chateau Marmont entrance,” Lana Wood writes in “Little Sister,” alleging that the incident happened in the summer of 1955, around the time Natalie Wood was filming “The Searchers.” The meeting had been arranged by their mother, Maria Zakharenko, who thought that “many doors might be thrown open for her, with just a nod of his famous, handsome head on her behalf,” according to Lana Wood.

“It seemed like a long time passed before Natalie got back into the car and woke me up when she slammed the door shut,” she writes. “She looked awful. She was very disheveled and very upset, and she and Mom started urgently whispering to each other. I couldn’t really hear them or make out what they were saying. Something bad had apparently happened to my sister, but whatever it was, I was apparently too young to be told about it.”

Douglas himself acknowledged that he was a womanizer and an unfaithful husband. Speaking to The Associated Press about Douglas in December 2016, less than a year before the #MeToo movement caught on, the actress and dancer Neile Adams lightheartedly said of her friend, “You could not sit beside him without his hand crawling up your leg.”

The Associated Press contributed to this report.