LOS ANGELES (CBSLA) – Actor Robert Wagner is considered a person of interest in the 1981 drowning death of his wife actress Natalie Wood, Los Angeles County Sheriff’s investigators told CBS’ “48 Hours.”

On Nov. 28, 1981, Natalie Wood went missing while on her family’s yacht off the coast of Catalina Island. Also aboard were Wagner, actor Christopher Walken and Capt. Dennis Davern. The following morning her body was found by authorities floating in the water. An autopsy report found several bruises on her body.

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“She looked like a victim of an assault,” LASD Detective Ralph Hernandez told 48 Hours.

FILE — Robert Wagner with Natalie Wood on April 23, 1972. (Getty Images)

The case was initially ruled an accident, but was reopened in 2011 by LASD. The L.A. County coroner’s office in 2012 changed the cause of death on Wood’s death certificate from accidental drowning to “drowning and other undetermined factors.” A new report was released in 2013.

“As we’ve investigated the case over the last six years, I think he’s more of a person of interest now,” sheriff’s Lt. John Corina said in an interview with 48 Hours.

Wagner has refused to speak to investigators since the case was reopened, 48 Hours found.

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“I haven’t seen him (Wagner) tell the details that match all the other witnesses in this case,” Corina said. “I think he’s constantly changed his story a little bit. And his version of events just don’t add up.”

Wagner is also believed to be the last person that saw Wood alive.

“I think it’s suspicious enough to make us think that something happened,” Corina told 48 Hours.

“We have not been able to prove this was a homicide. And we haven’t been able to prove that this was an accident, either,” Hernandez said. “The ultimate problem is we don’t know how she ended up in the water.”

CBS2 News asked Wagner’s publicist if he could comment on the case, and they said the actor did not.

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The 48 Hour special: “Natalie Wood: Death in Dark Water,” will air Saturday, Feb. 3 at 10 p.m. on CBS2.