Los Angeles County sheriff's officials say actress Natalie Wood's drowning is now being probed as a 'suspicious death' after new witnesses emerged.

The announcement from sheriff's homicide detectives comes hours after CBS News aired an interview with an investigator who said Wood's husband, actor Robert Wagner is considered a 'person of interest' in her 1981 death.

Wood disappeared after a night of drinking on a yacht with her husband and others. Her body was found later floating in the water.

It was declared an accident but police reopened the case in 2011 to see whether Wagner or anyone else played a role.

Sheriff's officials say one new witness described hearing yelling and crashing sounds coming from the couple's stateroom.

They said other witnesses saw a man and woman arguing on the back of the boat.

The revelation was made by Los Angeles County Sheriff's Department Lieutenant John Corina in a new documentary which will air on CBS on Saturday.

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Robert Wagner has been named as a person of interest in the death of his late wife Natalie Wood who drowned mysteriously in 1981. They are pictured together on the boat from which she vanished in 1981, two weeks before she died

'As we've investigated the case over the last six years, I think he's more of a person of interest now.

'I mean, we know now that he was the last person to be with Natalie before she disappeared,' he said.

Wagner, who is now 87 and married to actress Jill St. John, did not immediately respond to DailyMail.com's questions on Thursday morning.

Wood drowned while boating with her husband and their friend, actor Christopher Walken, off the island of Catalina in Southern California in November 1981.

The trio had just enjoyed a boozy dinner at an upscale restaurant when they were seen going back to the boat at around 10pm the night before Natalie was found.

In 2013, her sister revealed claims made by the boat's captain that Wagner had pushed Natalie overboard by accident and that he refused to help her once she was in the water.

The actress, who was 43 when she died, was found floating in the water in her nightgown the next morning.

Police in Los Angeles say they want to speak to Wagner, who is now 87, about Wood's death. The actor is pictured in April 2017

Wagner's explanation for her death was that it was a tragic accident.

He said Wood fled the boat in a rubber dinghy after watching him and Walken get into an argument about her career.

He claimed the last time he saw her was when she was 'fixing her hair' in the bathroom and that when he went to bed, she was not there.

Authorities accepted his version of events at the time and declared the actress's death an accident.

But in 2011, they reopened the investigation after receiving requests from both Natalie's sister Lana and the boat's captain, Dennis Davern, who suddenly confessed that he had lied about what happened.

She looked like the victim of assault Los Angeles County Sheriff's Department Detective Ralph Hernandez

He would not explicitly blame Wagner, but said an argument he and his wife had before she died was what caused her death.

An autopsy suggested that she had been the victim of an assault and had abrasions on her forehead.

Police have still not declared Natalie's death a murder and no charges have been filed against Wagner.

Detectives however believe he knows more than he revealed at the time.

'I haven't seen him tell the details that match all the other witnesses in this case.

'I think he's constantly changed his story a little bit. And his version of events just don't add up.

'I think he does [know more] because he's the last one to see her,' Corina said.

Wood drowned near her yacht, the Splendour, off the coast of Catalina in southern California in November 1981. Her husband said they had argued and that she took off in the rubber dinghy and somehow must have fallen into the water

An autopsy report showed that Wood had suffered a cut to her face which police say may show she was assaulted before she died

Christopher Walken (left in October and right, with Wood filming Brainstorm together in 1981) was also on the boat at the time

He would not explicitly say whether he believed the actress was the victim of murder, but said: 'I think it's suspicious enough to make us think that something happened.

'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.

'The ultimate problem is we don't know how she ended up in the water,' he added.

Detective Ralph Hernandez said Wood 'looked like the victim of assault' when she was pulled from the water.

Captain Davern, who was on the boat when Wood disappeared, participated in the documentary.

'I remember people coming on to the boat, saying they had found Natalie Wood. I just couldn't believe it,' he said in a teaser for the show.

He, along with the actress's sister Lana pleaded with police to reopen the case in 2011.

Lana always maintained that Wagner held the key to her death and she lambasted him for not being forthcoming with police.

In 2011, she told DailyMail.com how she had received death threats from his fans for not dropping her crusade.

Los Angeles County Sheriff's Department Lieutenant John Corina says he believes Wagner has never told the full story of his wife's death

Captain Dennis Davern was on the boat on the day Wood vanished. He asked for the investigation to be reopened along with Wood's sister Lana (right) who told DailyMail.com in 2011 that she believed Wagner was responsible for her sister's death

Wagner is pictured with his current wife Jill St John. They married in 1990 and remain together

'After 35 years I feel we're so close to finding out what happened to my sister but the LA Attorney's Office is refusing to press charges against Robert Wagner - the man I believe is responsible.

'It's a cover-up and I won't rest until Natalie gets justice,' she said at the time.

In 2013, she revealed that Davern had once told her that her sister was pushed overboard by her husband and that he refused to help her once she was in the water.

They were drunk after a night of heavy drinking and Wagner, whom she called RJ, did not appear to understand how dangerous it was, she claimed.

'He said it appeared to him as though RJ shoved her away and she went overboard. Dennis panicked and RJ said, "Leave her there. Teach her a lesson."

The medical examiner found undigested food in Wood's stomach which suggested she had died at around midnight, two hours after she, Wagner and Walken were seen leaving the restaurant where they had dinner.

In 2013, Lana was seen confronting Wagner in a Palm Springs hotel at a lunch to honor his third wife, Jill St. John.

Wagner spoke out in 2016, 35 years after Wood's death, to insist it was a tragic accident which 'shattered' him.

The couple had their own children but Wagner also looked after Wood's daughter from a previous marriage after her death. They are seen in 1972

Wood and Wagner were Hollywood darlings and their turbulent romance ignited their fame. hey are seen in 1980 (left) and in 1974 (right)

He had previously claimed in a 2009 memoir that he argued with both Wood and Walken on the night in question and that Wood vanished afterwards, taking the dinghy from her family's yacht to get herself to shore.

'The last time I saw my wife she was fixing her hair in the bathroom while I was arguing with Chris,' he said. 'I saw her shut the door. She was going to bed.'

He described how he and Walken moved up to the deck as 'things were threatening to get physical' and they were calmed by the fresh sea air.

He said he waited up a little longer before going to bed – but his wife was not there.

'Yes, I blamed myself,' the actor wrote. 'If I'd been there, I could have done something. I wasn't, but ultimately, a man is responsible for his loved one.

Wagner is seen comforting Wood's daughter Natasha at her funeral. He later said her death 'shattered' the family

'I would have done anything in the world to protect her. Anything. I lost a woman I loved with all my heart and I will never completely come to terms with that.'

Wood shot to fame as a child star in Miracle in 34th Street and later appeared in films including Gypsy and Rebel Without a Cause.

Wagner, a star in his own right, were darlings of the film industry and their turbulent romance rivaled that of Elizabeth Taylor and Richard Burton.

Wood and Wagner were married twice; first in 1957 and again in 1972. They both married others in between.

In 1969, Wood married British film agent and director Richard Gregson and the pair had a daughter together.

Wagner married Marion Marshall a year after his first split from Wood. They were together for eight years and had a daughter together, Katie.

In 1972, he and Wood reunited and in the same year, she gave birth to their only biological child together, Courtney.

CBS 48 Hours Natalie Wood: Death in Dark Water will air on Saturday, February 3 at 10pm EST.