LOS ANGELES — The Los Angeles County Sheriff’s Office is reopening its investigation into the death of Natalie Wood, authorities said Thursday. The Academy Award-nominated actress, known for her roles in “West Side Story” and “Rebel Without a Cause” drowned in 1981 while boating near Catalina Island, Calif.

Even though the autopsy report shows she had two dozen bruises on her body, including on her left cheek and arms, the actress’s death was ruled an accident. Lana Wood, Natalie’s sister, and actor Robert Wagner, the captain of the yacht on which Wood was last seen, asked the sheriff’s office to reopen the case last year. Homicide investigators are now revisiting the case after they were contacted by people who claimed they had “additional information” about the incident, the sheriff’s department said in a statement.

It is still unclear whether the sister and yacht captain are the parties responsible for persuading the sheriff’s department to reopen the case.

In addition to the bruises, questions have surrounded the case ever since the coroner ruled the drowning an accident. According to police reports, Wood was found floating a mile away from the yacht wearing a nightgown, socks, and a down jacket.

“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. “I just want the truth to come out, the real story.”

Dennis Davern, the former captain of the yacht Splendour has said he believes Wood’s death was a direct result of a fight she had with Wagner that night, a fight Wagner acknowledges occurred in his 2009 book “Pieces of My Heart.”

Police spoke to the owner of the yacht Rob Nelson Saturday. Details of the conversation have not been released.