The Rebel Without a Cause star drowned off the coast of California in November, 1981 during a trip on a luxury yacht with her husband Wagner and their guest, actor Christopher Walken.
Her death was ruled an accident, but authorities announced on Thursday that they have since re-opened the case.
Officials from the Los Angeles County Sheriff's Department held a press conference on Friday (18Nov11) and revealed they had decided to look into Wood's death after receiving new information "substantial enough" to warrant a fresh investigation.
Lieutenant John Corina refused to provide details about the latest developments, but declared that Wagner is not being treated as a suspect.
Two homicide detectives have been assigned to the case, although authorities have yet to reveal whether Wood's body would be exhumed, or if Walken would be interviewed about the 30-year-old incident.
Wood's sister Lana has welcomed the new investigation, telling TMZ.com her sibling "deserves the truth".
The press conference took place hours after the boat's captain, Dennis Davern, confessed on U.S. TV's Today show that he had lied to police during the initial investigation, admitting he had "made mistakes by not telling the honest truth". He went on to claim that Wagner was "responsible" for Wood's death.