Los Angeles (CNN) -- Information gathered by a renewed investigation into actress Natalie Wood's 1981 drowning death has persuaded the Los Angeles coroner to remove "accidental" from her death certificate, a detective said.
The death certificate was amended on August 7 to list her death as caused by "drowning and other undetermined factors" rather than "accidental drowning," Los Angeles County Sheriff's Detective Kevin Lowe said Wednesday.
Lowe and a partner are still working the case, which is an open and active investigation, Lowe said.
Last November, homicide investigators decided to take a new look at one of Hollywood's most enduring mysteries after they were contacted by people who said they had additional information about the actress's drowning, the sheriff's department said.
"This new information is substantial enough to make us want to take a new look at the case," Lt. John Corina said at the time.
The announcement persuaded tipsters to come forward with additional "intriguing" information, sheriff's spokesman Steve Whitmore told CNN last January.
Investigators did not comment directly on statements made in news reports in November by Dennis Davern, the captain of a yacht owned by Wood and her husband, actor Robert Wagner.
Davern offered a new account of how Wood's death was reported, saying that Wagner waited hours to call the Coast Guard after Wood went missing off Catalina Island, near the California coast, following an argument the couple had.
Authorities haven't gone into specifics about who has been interviewed, but they did say when they reopened the case that Wagner wasn't a suspect.
Wood drowned in the Pacific Ocean on November 29, 1981, off the isthmus of Catalina Island. She once said in a televised interview that her greatest fear was of dark seawater.
Her body was found floating in the water about a mile away from the yacht, in a long nightgown, socks and a down jacket, according to police reports.
The autopsy report showed the actress had two dozen bruises on her body, including a facial abrasion on her left cheek and bruises on her arms.
"My sister was not a swimmer and did not know how to swim, and she would never go to another boat or to shore dressed in a nightgown and socks," said Lana Wood, referring to theories that the actress voluntarily jumped from the boat.
Although the county coroner's office ruled at the time that Wood's death was an accident, others say the case hasn't made sense.
In 2010, Lana Wood told CNN she believes a highly charged argument between her sister and Wagner on the yacht's back deck preceded Wood's drowning. She told CNN last year she does not suspect foul play.
"I just want the truth to come out, the real story," she said.
Davern, the former captain of the yacht Splendour, broke his long silence with a detailed account of that day in "Goodbye Natalie, Goodbye Splendour," a book he wrote with his friend Marti Rulli. It was published in September 2009.
Davern has said he believes Wood's death was a direct result of a fight with Wagner.
In a lengthy interview with CNN in 2010, Davern said he now believes the investigation of Wood's death was incompetent and suggested there was a cover-up. He said he regrets misleading investigators by keeping quiet at Wagner's request.
Wood and Wagner married in 1957, divorced in 1962, then remarried in 1972. They often sailed their yacht off the coast of California, and they invited Wood's "Brainstorm" co-star, Christopher Walken, to join them on a sail on Thanksgiving weekend in 1981.
The Hollywood rumor mill was abuzz with speculation that Wagner was jealous of Walken, but authorities have said Walken witnessed only the events leading up to an argument between the couple.
Wagner admitted his jealousy in his book "Pieces of My Heart," also published in September 2009. He acknowledged that there had been a fight with Wood, writing that he smashed a wine bottle on a table.
After Wagner argued with Walken and broke the wine bottle, Wood left in disgust and went to her stateroom, Davern told CNN. Walken also retired to a guest room, Davern added, and Wagner followed his wife to their room. A few minutes later, Davern said, he could hear the couple fighting.
Embarrassed, Davern said, he turned up the volume on his stereo. At one point, Davern recalled, he glanced out of the pilot house window and saw Wagner and Wood on the yacht's aft deck. "They'd moved their fight outside ... you could tell from their animated gestures they were still arguing," he said.
A short time later, Wagner, appearing to be distraught, told Davern he couldn't find Wood. Davern searched the boat but couldn't find her. He noticed the rubber dinghy also was missing.
Wagner shrugged and poured them both drinks, Davern said. He suggested his wife had probably gone off in a temper.
Wagner's story, as told in his book, differs from Davern's. He maintains that after the argument with Walken, Wood went to her room and prepared for bed while he and Walken sat on the deck, cooling off.
Wagner writes that he went to check on Wood, but she wasn't there. He maintains that he and Davern searched the boat and noticed the dinghy was missing. Wagner assumed his wife had gone ashore on her own, he wrote.
He radioed the restaurant on shore where they'd had dinner and called the harbor master to see if anyone had seen Wood.
The dinghy was found about a mile away from the yacht, and a mile from where Wood's body was found.
Wood's first starring role was as a child in "Miracle on 34th Street" in 1947, and she played alongside some of Hollywood's top leading men -- James Dean in "Rebel Without a Cause" and Warren Beatty in "Splendor in the Grass." She was nominated for Oscars in both of those films, as well as for "Love with the Proper Stranger" (1963), according to IMDb. One of her more memorable roles was as Maria in "West Side Story."
Wagner's striking good looks landed him roles in dozens of films in the 1950s and '60s before he hit it big in television. He starred in two popular series, "It Takes a Thief" (1968-70) and "Hart to Hart" (1979-84), and more recently as Number Two in the "Austin Powers" spy spoofs.
CNN's Michael Martinez, Kareen Wynter and Jane Caffrey contributed to this report.