LOS ANGELES (CBSLA.com) — Questions have long lingered over the death of iconic Hollywood star Natalie Wood.

The three-time Oscar-nominated actress was believed to have drowned in November 1981 off the coast of Catalina Island, but coroner’s officials recently changed the cause of death from “accidental drowning” to “other undetermined factors.”

CBS News has uncovered new information in the investigation on Wood’s mysterious death; audio interviews with the actress’ younger sister, Lana, discussing what she knew of her death.

“I have boxes of research materials that really can’t be found anywhere else. I have tapes of all the interviews that I’ve conducted,” said author Suzanne Finstad, who collected the information for her 2001 biography on Wood’s life.

Finstad told CBS show “48 Hours” that she shared her extensive archive with detectives, including the audio interviews she conducted with Lana.

Lana Wood said that more than a decade after her sister’s death, she received a phone call from Dennis Davern, the captain of the “Splendour”. Davern, Wood, her husband Robert Wagner (nicknamed “RJ”) and fellow actor Christopher Walken were aboard the ship the night the actress died.

“Dennis was obviously drinking…Dennis was not a close friend, and I don’t know why he decided to call me,” she can be heard telling Finstad.

Davern allegedly told Lana that he knew what really happened to her sister the night of her fatal voyage.

“He said it appeared to him as though RJ shoved her away and she went overboard. Dennis panicked and RJ said, ‘Leave her there. Teach her a lesson.’ Dennis said he was very panicky that he was sitting and RJ kept drinking and kept drinking. And he’d say, ‘Come on, let’s get her.’ And he said RJ was in such a foul mood, at that point, that he then shut up and was waiting for when, when are they gonna go to her rescue, until all the sound stopped.”

Lana Wood goes on to say that Davern did not think Wagner meant for his wife to die.

“You know, he didn’t mean for her to drown. But he didn’t run to her aid.”

She believed Davern when he said it was an accident.

“Even if he did not kill her, which is what I understand the guy’s saying, it was– you know, that it– it was an accident,” Lana said.

The tapes could be of vital importance to the investigation if detectives determine there’s any truth to them and if they will hold up in court.

Lana Wood has never told this story publicly.

Actor Robert Wagner did not return CBS2’s request for a statement Thursday night.

“48 Hours” tried to verify the account with Lana Wood and Davern, but they would not comment.

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