Actress Natalie Wood portrays character 'Maria" in scene from 1961 film "West Side Story" in this undated publicity photograph released to Reuters on November 18, 2011. (Courtesy 20th Century Fox Home Entertainment/Handout)

Officials in Los Angeles have changed the cause of Hollywood icon Natalie Wood's death to "undetermined", according to a new report.

The actress drowned in 1981 after partying on a yacht off the Californian coast with her husband Robert Wagner and Christopher Walken.

The tragedy was ruled an accident but the case was re-opened last year after detectives received new information about the night Wood died.

Now the Los Angeles County Coroner has amended her death certificate, changing the cause of the tragedy from an "accident" to "undetermined", according to TMZ.com.

The website reports the investigation into the incident is still ongoing.