The re-opening of the case was prompted by new information received by detectives, according to Los Angeles County sheriff's spokesman Steve Whitmore.
The Rebel Without a Cause star died off the coast of California in November, 1981 during a trip on a luxury yacht with her husband Robert Wagner and their guest, actor Christopher Walken. Her death was ruled an accident.
Last year (10), her sister Lana demanded the case be re-opened, insisting modern crime-solving technology would help unravel the mystery once and for all - and on Thursday (17Nov11), officials announced her death will be investigated once again.
A press conference about the case is due to be held on Friday (18Nov11), and Wood's widower has welcomed the developments.
Wagner's spokesperson Alan Nierob says, "Although no one in the Wagner family has heard from the L.A. County Sheriff's department about this matter, they fully support the efforts...
"(The family) trust they 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."