She was found floating face down 100 yards from shore, a woman who had declared herself “terrified of water, dark water, seawater”.

The actress Natalie Wood, once “the most beautiful teenager in the world”, a luminous talent who garnered three Oscar nominations before she was 25, was dead from drowning aged 43.

This, the world was soon told, had been a tragic accident. James Dean’s Rebel Without a Cause co-star had died after falling from the 60ft yacht Splendour she shared with her husband Robert Wagner, of TV’s Hart to Hart.

Just two weeks after the actress was found dead off California’s Catalina Island, the case was closed: “Strictly accidental”, ruled the Los Angeles County Coroner Thomas T Noguchi.

Ms Wood had probably slipped and fallen into the water on the night of 28 November 1981 as she tried, on her own, to untie the yacht’s 13ft inflatable dinghy and climb into it.

The grief-stricken Mr Wagner took to his bedroom, refusing all visitors including the actress Elizabeth Taylor.

“If I'd been there,” he wrote decades later, “I could have done something. I wasn’t.

“I would have done anything in the world to protect her. Anything. I lost a woman I loved with all my heart.”

Now though, a very different version of events has emerged.

Mr Wagner, the grieving husband, has now been described by the Los Angeles County Sherriff’s Department as “a person of interest” in the case.

And in a CBS 48 Hours documentary broadcast on Saturday night, Mr Wagner was recast as a jealous husband, angry at the attention his wife was paying to Christopher Walken, her co-star in the upcoming thriller Brainstorm.

Aged 38 to Wagner’s 51, an Oscar nominee to Wagner’s film career in B-movies, Walken had been invited onto the yacht despite Hollywood rumours about how close he was getting to Wood.

The 48 Hours documentary didn’t just repeat the testimony of the yacht’s captain Dennis Davern, that Wagner had smashed a wine bottle and screamed at Walken – “Do you want to f*** my wife?”- before having a violent drunken row, alone, with Wood, and telling her “Get off my f***ing boat”.

The programme went further and said a pair of detectives had now found two new witnesses who could for the first time corroborate Mr Davern’s evidence of a row between Wagner and Wood near the stern of the yacht.

One witness supposedly heard the row. The other, 48 Hours reported, “Saw figures, a male and a female, whose voices they recognised as being Robert Wagner and Natalie Wood arguing in the back of the boat.”

The witnesses were not named, nor were their whereabouts when they heard the row made public. But the detectives said they were “very credible”, and 48 Hours reported that they also backed Davern – who first went fully public in 2011 – in one potentially sinister detail: they claimed the argument stopped suddenly, to be followed by complete silence.

The detectives, it should be said, have not declared Mr Wagner as a suspect in the case. Indeed, the 87-year-old actor has never been named as a suspect and has never wavered from his insistence that he was both grief-stricken and innocent when his wife died.

But now, inevitably, speculation is focusing on where Mr Wagner’s showbiz image might end and his reality begin.

It is hard to miss the irony that when his wife died after disappearing from a 60ft yacht, Mr Wagner was the star of the popular TV series Hart to Hart: “Millionaire sleuths solve mysteries while enjoying wedded bliss,” was how one fan remembered it fondly.

“My favourite part was to see such a happy and nice looking couple as Jonathan and Jennifer [Hart]”, remembered another fan.

“The people they fought were incidental to the show to me,” she added.

Of course they were. On TV, the baddies – who most weeks were murderers – were always caught and the mystery neatly resolved by the end of every episode. Allowing the fabulously wealthy Harts to get on with living the American dream.

“What I liked most about the show,” wrote the fan, “Was how close the Harts were and also how very happily married.”

Which was precisely the role America ordained for Wood and Wagner when they first married in 1957.

She was the 19-year-old named by LIFE magazine as “the most beautiful teenager in the world”.

He was the 27-year-old “golden boy” with matinee idol looks. Their marriage was described as "the glittering union of the 20th Century".

Riddle of Natalie Wood's final hours Show all 6 1 /6 Riddle of Natalie Wood's final hours Riddle of Natalie Wood's final hours IA32-Natalie-Wood-main.jpg Hollywood actress Natalie Wood Rex Features Riddle of Natalie Wood's final hours IA19-32-Natalie-Wood-2.jpg The star with her husband Robert Wagner Rex Features Riddle of Natalie Wood's final hours IA19-31-Natalie-wood-3.jpg Natalie Wood with Christopher Walken in her last film 'Brainstorm' Rex Features Riddle of Natalie Wood's final hours IA19-31-Natalie-wood-4.jpg AP Riddle of Natalie Wood's final hours IA19-31-Natalie-Wood-5.jpg MSNBC.COM/TODAY Riddle of Natalie Wood's final hours nataliewood.jpg AP

“People expected [their] place to be the last word in the American dream,” recalled their friend, the playwright Mart Crowley, “A doll's house with dolls living in it.”

And yet by 1962, they were divorcing, with Ms Wood alleging “mental cruelties” by her husband.

Robert Wagner once told a television interviewer: “It was basically my inadequacy that didn’t make it work”.

48 Hours has now alleged more disturbing detail. The documentary said the detectives had traced a former neighbour, who claimed to remember that when he was 12, a terrified Natalie Wood had banged on the door of his family house late one night.

The programme quoted Lieutenant John Corina, of the Los Angeles County Sherriff’s Department as saying: “She was so afraid of him. She ran to a neighbour's house yelling … ‘he's gonna kill me’. And looking for help and looking for safety. And so a neighbour took her in.”

Wood returned home the next morning. The detectives told 48 Hours they have found no other allegations of possible violence in the first Wood-Wagner marriage.

And friends said that despite divorcing, the couple remained “besotted” with each other.

By 1972 the couple had split from their respective new partners to get back together and remarry.

Ms Wood’s younger sister Lana, however, now seems to have rather lukewarm memories of the reunion.

She told 48 Hours that after telling her she was remarrying Mr Wagner, Ms Wood “looked down, and said, ‘Sometimes, it's better to be with the devil you know than the devil you don't.’"

But by 1977 Wood and Wagner seemed to be back living the American dream.

The couple invited a TV interviewer into their beautiful home. With Ms Wood’s daughter Natasha – by Richard Gregson, her second husband – playing piano in the background, Mr Wagner smiled and said: “I’m sure glad it’s all worked out.”

At about the same time, Ms Wood told an interviewer about her fear of dark water.

"I had a mean director one time who threw me in the ocean," she revealed. "I was terrified, petrified, because we were in the open ocean.”

And then, in 1981, came the Thanksgiving weekend on the yacht, with the married couple, the skipper and Walken.

Natalie Wood with Christopher Walken, as they appeared in a publicity still for 'Brainstorm' (Rex Features)

At the time, in public, even suggestions of an argument between Walken and Wagner were played down.

When the coroner tentatively mentioned a “non-violent argument” between the two men, a sheriff’s homicide investigator told the Los Angeles Times: “I don’t know where the coroner got that information.”

And as to what Ms Wood, a weak swimmer terrified of dark water, would be doing with a dinghy, late at night in rough seas, while wearing only a nightgown, socks and a red down jacket, the investigator had a ready answer: “According to the people we talked to, it was not uncommon for her to take the dinghy out on a nice night. She was very familiar with it.”

Mr Wagner developed his own theory, one that might explain both the bruises found on his wife’s body, and, possibly, the scratch marks on the rubber dinghy.

In his 2009 autobiography Pieces of My Heart, he wrote that as he was on one of the top decks while his wife was trying to sleep in the cabin: “Natalie obviously had trouble sleeping with that dinghy slamming up against the boat.

“She probably skidded on one of the steps after untying the ropes. The steps are slick as ice because of the algae and seaweed that's always clinging to them. After slipping on the steps, she hit her head against the boat... I only hope she was unconscious when she hit the water."

But despite – or perhaps because of – officialdom wrapping it up so quickly, the case was the subject of whispering and innuendo almost from the start.

And much of it stemmed from the skipper, Mr Davern. 48 Hours and others have said he has not been an entirely consistent witness.

He told investigators in 1981 that he had seen nothing untoward. But eventually, Mr Davern started selling another story – or partial versions of it – to reporters.

One of the first versions, given to the Globe as “Natalie Wood, the Shocking Truth About Her Death”, revealed a row on the night of 28 November – but only between Walken and Wagner, with no mention of any confrontation between husband and wife.

This version could, in fact, have been said to have tallied with what Wagner wrote in his 2009 autobiography, in which he too admitted an argument with Walken, about Ms Wood’s career (rather than the Oscar winner’s intentions towards his wife).

Then, having co-authored a book about the case, in 2011 Mr Davern gave a statement to the Los Angeles County Sheriff’s Department.

This seems to be the version he has stuck with ever since – and it was sufficiently explosive to see the whole case reopened.

He claimed Mr Wagner had confronted Walken about wanting to “f*** my wife”. Then, he said, after Walken retreated to his cabin and went to sleep, he heard the sounds of a “terrible argument” between Wood and Wagner in the stateroom cabin.

“I heard things (objects, possibly people) hitting the walls and things being thrown at the ceiling,” the skipper said in his 2011 statement.

“Then I heard voices again on the deck.

“The only full sentence I could completely decipher during the entire argument was ‘Get off my f***ing boat’ said by Robert Wagner.”

When he arrived on the rear deck 15 minutes later, Mr Davern said, “Only Robert Wagner was present. [He] appeared sweaty, flustered, anxious, nervous and dishevelled. He told me ‘Natalie is missing’.”

Mr Davern said he wanted to radio for help, but with the dinghy also missing, Mr Wagner instructed him to wait before raising the alarm, suggesting Ms Wood had gone ashore and would return.

“Robert Wagner opened scotch and poured alcohol for me,” wrote Mr Davern. “He encouraged me to drink. He discussed with me the repercussions of bringing immediate attention to the situation.”

According to Mr Davern, the star of Hart to Hart had seemed keen for his real marriage to appear as untroubled as his onscreen one.

“Robert Wagner,” he wrote, “Claimed he did not want to tarnish his image by drawing public attention to the situation.”

Mr Davern said the coastguard was only called at 3.30am, some three hours after Mr Wagner first told him his wife was missing.

And then, claimed Mr Davern, after Ms Wood’s body was found, “I was told to say nothing and that I was to see an attorney in the next day or two to sign a statement being prepared for me, which I did sign, after barely reading it.”

The skipper said Mr Wagner invited him to live with him at his Beverly Hills home.

“Mr Wagner even secured a job for me as a general-extra actor on his TV show Hart to Hart,” wrote Mr Davern.

But, he said, his conscience began bothering him – he would later tell journalists that staying at the Wagner mansion was like being kept a virtual prisoner.

“I couldn’t walk out the front door,” he claimed. “Somebody was always there, usually Wagner’s bodyguard. I felt really closed in.”

He wasn’t, he insisted, telling his story for the money. “What I really want,” he insisted in 2011, “Is to give Natalie a voice.”

Via his publicity team, however, Mr Wagner responded with a statement strongly hinting that some people were trying to cash in on his wife’s passing: “The Wagner family … fully support the efforts of the sheriff's department and trust they will evaluate whether any new information comes from a credible source or those simply trying to profit from the 30-year anniversary of her tragic death."

And in this, Mr Wagner was backed by one of the original detectives, Duane Rasure.

“Obviously he [Davern] was trying to sell a book and make money off of it,” Mr Rasure told reporters in 2011.

“If I have ever the slightest inkling there was a murder, something suspicious, I would have worked it. I did not cover for anybody and I wouldn't cover for anybody.”

Mr Rasure added that he accepted Wagner’s explanation that he waited before raising the alarm because he had been under the impression she had gone ashore in the dinghy.

“He [Wagner] did call and have the people on the shore search,” Mr Rasure added.

The reopening of the 2011 case seemed, ultimately, to have altered little.

The only visible change was that in 2012 Wood’s death certificate was amended to change the cause from “accidental death” to “drowning and other undetermined factors”.

This, reporters were told, was because investigators couldn't rule out that some of the bruises on Ms Wood's body happened before she went into the water.

But now Detective Ralph Hernandez, of Los Angeles County Sheriff's Department, has told 48 Hours that those two dozen bruises had made Wood look “like the victim of an assault”.

He and his colleague John Corina told the documentary that behind the scenes, the publicity surrounding the reopening of the investigation in 2011 prompted new witnesses to come forward, yielding between 100 and 150 new clues – and the new witnesses who seem to back up Mr Davern.

For all the previous shifts in his evidence, the two cops now believe the old skipper is a credible witness.

Mr Corina told 48 Hours: “His version of events … Makes more sense of what happened and is corroborated by other people.”

But as for Wagner – who has always denied rowing with his wife on the night in question – Corina told 48 Hours: “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.”

Once described as 'the most beautiful teenager in the world', Natalie Wood had three Oscar nominations before she was 25 (Rex Features)

Mr Corina and Mr Hernandez told 48 Hours that despite several attempts, including a trip to Aspen, where Wagner lives with the actress Jill St John, his third wife, the star has declined to speak to them.

That may, of course, simply be because Wagner now feels he has no new information to add.

His attorney Blair Berk said as much in 2011, issuing a statement which read: "Mr Wagner has fully cooperated over the last 30 years in the investigation of the accidental drowning of his wife.

"Mr Wagner has been interviewed on multiple occasions by the Los Angeles sheriff's department and answered every single question asked of him by detectives during those interviews."

Mr Corina and Mr Hernandez, for their part, are insistent that they won’t close the case “until we get the truth”.

What they could do with that truth, however, is another matter. As 48 Hours confirmed, after more than 36 years the statutes of limitations have run out on all possible offences except murder. And to prove murder, the cops will need to prove someone deliberately forced Ms Wood into the sea with the intention of killing her.

Without the intent to kill, manslaughter, even failing to help Ms Wood once she was in the dark water would yield no criminal legal action.

And, for now, as Detective Hernandez acknowledged, “The ultimate problem is we don't know how she ended up in the water. We have not been able to prove this was a homicide. And we haven't been able to prove this was an accident, either."