The body of Wood, 43, was found floating in a Catalina Island cove in 1981 and her death was ruled an accidental drowning by the Los Angeles County Coroner.
The star of Rebel Without a Cause and West Side Story had spent the night before dining and drinking on the island and on a yacht with her husband, television star Robert Wagner, and actor Christopher Walken.
Questions over the circumstances of Wood's untimely death have lingered for 30 years and family members have previously asked for authorities to reexamine the original findings.
"Recently sheriff's homicide investigators were contacted by persons who stated they had additional information about the Natalie Wood Wagner drowning," the department said in a statement.
"Due to the additional information, Sheriff's Homicide Bureau has decided to take another look at the case."
A spokesman declined to elaborate on the additional information pending a news conference set for Friday morning.
But Los Angeles County Sheriff Lee Baca told the Los Angeles Times detectives wanted to talk to the captain of the yacht, the Splendor, about comments he had made as the 30th anniversary of Wood's death approached.
The Times, citing anonymous sources, reported the sheriff's department also received an anonymous letter saying the captain had new recollections about the case.
A spokesman for Wagner said the actor's family had not been contacted by the sheriff's officials but "fully supports" the department's efforts.
The family members trust investigators "will evaluate whether any new information relating to the death of Natalie Wood Wagner is valid and that it comes from a credible source or sources, other than those simply trying to profit from the 30-year anniversary of her tragic death," spokesman Alan Nierob said in the statement.
The department asked that anyone with information contact homicide investigators or an anonymous tip line.
Wood, born Natalia Nikolaevna Zakharenko to Russian immigrant parents in San Francisco, appeared as a child in such films as the Christmas classic Miracle on 34th Street and The Ghost and Mrs. Muir.
She was nominated for a best supporting actress Oscar as a teenager for her role opposite James Dean in the classic 1955 film Rebel Without a Cause.
Wood was nominated twice for best actress Oscars, for parts in 1961's Splendor in the Grass and Love with the Proper Stranger two years later. She never won the award.
