With HBO's release of Natalie Wood: What Remains Behind, the strange details of the Hollywood star's shocking death are being sifted through once more. Among them, what did Christopher Walken see that night aboard Splendour? Though a witness to the goings-on that led up to Wood's drowning, Walken is not interviewed in the new documentary. However, over the years the eccentric actor has made public statements that make pretty clear where he stands on whether Wood died by accident or at the hands of her husband, Robert Wagner.

First a bit of background: It was during the Thanksgiving holiday of 1981 when Wood invited Walken to join her and Wagner for a weekend boat trip to Catalina Island. According to Natalie Wood: What Remains Behind, other friends--including Delphine Mann and Mart Crowley--were invited as well but didn't attend. Walken and Wood were in the midst of co-starring in the sci-fi movie Brainstorm. After shooting on location in North Carolina, the production had moved to Los Angeles for studio interiors. However, they were on hiatus for the holiday. As Walken wasn't an LA native, Wood wanted to offer him a friendly place to stay during the break.

That Saturday, Walken, Wood, and Wagner went ashore to grab drinks and dinner at the Doug's Harbor Reef Restaurant, then returned to the 60-foot yacht called Splendour. There, the party continued with more drinks below deck, but things grew tense. The doc features an interview with Wagner, in which he admits that he and Walken got into a heated argument, during which Wood's husband smashed a wine bottle.

Wagner claims Walken was urging Wood, who'd taken a step back from the limelight to raise her and Wagner's children, to get back into the swing of movie stardom. "I think it's important she works," Wagner recalls Walken saying, to which the Hart To Hart star responded, "I think it's important you keep out of her life." However, the Splendour's captain Dennis Davern remembers Wagner's retort being more along the lines of "What are you trying to do? F*ck my wife?"

From here, Wagner and Davern's accounts differ dramatically, with the former posting a freak accident and the latter fingering Wagner for letting Wood drown. However, both agree that Walken went to bed at some point after the fight. As such, he was not a witness to whatever became of his co-star. For two years following the discovery of Wood's body, tabloids had a field day grasping at facts and speculation with equal fervor. Walken spoke to the police, but he didn't speak publicly about that night until 1983, when Brainstorm was finally slated for release.

Here's what Walken told ET:

"The real story of her death is that she drowned. Nobody knows how she drowned or what happened except her. That's what it is. There is no 'real story.' Nobody will ever know."

Here's the original video:

This answer didn't satisfy the fascinated public, so the press kept pressing. In a 1986 profile for People, Walken seemed irate that Wood's death was brought up:

When a topic rankles, he stonewalls. Tops on that list is the matter of Natalie Wood, his co-star in the 1983 film Brainstorm. Walken was on board the yacht with Natalie and her husband, Robert Wagner, the night she drowned. "I don't know what happened," snaps Walken. "She slipped and fell in the water. I was in bed then. It was a terrible thing. Look," he continues, his eyes icy, "we're in a conversation I won't have. It's a f----ing bore."

11 years later, Walken restated that Wood's death was an accident. Essentially, supporting Wagner's version of events, he told Playboy, "Anybody there saw the logistics -- of the boat, the night, where we were, that it was raining -- and would know exactly what happened. You hear about things happening to people - they slip in the bathtub, fall down the stairs, step off the curb in London because they think that the cars come the other way - and they die. You feel you want to die making an effort at something; you don't want to die in some unnecessary way."

"What happened that night only she knows, because she was alone," Walken continued, speculating. "She had gone to bed before us, and her room was at the back. A dinghy was bouncing against the side of the boat, and I think she went out to move it. There was a ski ramp that was partially in the water. It was slippery - I had walked on it myself."

In 2011, the investigation to Wood's death was reopened in part because of Davern's releasing a tell-all book, Goobye Natalie, Goodbye Splendour, which was all about that night and its alleged cover-up. When asked what he thought about this by a TMZ paparazzo, Walken said simply, "I don't know."

While Walken has tried to avoid this topic over the past 30-something years of his career and thousands of press interviews, the current investigators on the reopened case revealed he did speak with them. "His story has changed a little bit," CBS This Morning's Erin Moriarty reported, "Like what (Walken) said initially to police and then what he said in Playboy magazine...but they say he is not a person of interest."

The investigators note; however, that Wagner, who refuses to speak to the police any further, is a person of interest.

Natalie Wood: What Remains Behind premieres on HBO on May 5.