James Cameron has said he was told on Monday that the Titanic sub had imploded and says watching the rescue mission was "futile".
The Titanic film director and sea expert claims he was told of a noise that was likely the implosion of the OceanGate sub.
He said it didn't surprise him because he thought the carbon fiber hull of the sub named Titan was fundamentally unsuitable.
Cameron, who directed the 1997 film Titanic and has made over 30 dives to the wreckage, said his dives had been done in a ceramic sub which was more resistant.
"I tracked down some intel that was probably of a military origin, although it could have been research - because there are hydrophones all over the Atlantic - and got confirmation that there was loud noise consistent with an implosion," he explained.
James told CNN that he felt "heart sick from the outcome of this" but that he had been living with the news for a few days.
"I've been living with it for a few days now, as have some of my colleagues in the deep submergence community," he said.
"I was out on a ship myself when this happened on Sunday.
"The first I heard of it was on Monday morning. I immediately got on my network - because it's a very small community in the deep submergence group - and found out some information with about a half hour that they had lost comms and they had lost tracking simultaneously.
"The only scenario that I could come up with in my mind that could account for that was an implosion. A shockwave event so powerful it actually took out a secondary system that has its own pressure vessel and its own battery power supply, which is the transponder that the ship uses to track where the sub is."
He added: "I let all of my inner circle of people know that we had lost our comrades, and I encouraged everyone to raise a glass in their honor on Monday.
"Then I watched over the ensuing days this whole sort of everybody-running-around-with-their-hair-on-fire search, knowing full well that it was futile, hoping against hope that I was wrong but knowing in my bones that I wasn't."
James went on to say it "certainly wasn't a surprise" when it was confirmed on Thursday that all five onboard had died.
He isn't the only person to claim to know about the implosion before Thursday.
A senior U.S. Navy official told The Wall Street Journal in a statement: "The U.S. Navy conducted an analysis of acoustic data and detected an anomaly consistent with an implosion or explosion in the general vicinity of where the Titan submersible was operating when communications were lost.
"While not definitive, this information was immediately shared with the Incident Commander to assist with the ongoing search and rescue mission."
The five victims consisted of three British citizens including billionaire Hamish Harding. Shahzada Dawood and his son Suleman Dawood were also onboard along with French national and renowned diver Paul-Henri Nargeolet.
The fifth member of the team was OceanGate CEO and founder Stockton Rush, a former investment banker with an aerospace degree.
Cameron said when he heard OceanGate was making a deep-sea submersible with a composite carbon fiber and titanium hull he was skeptical.
"I thought it was a horrible idea. I wish I'd spoken up, but I assumed somebody was smarter than me, you know, because I never experimented with that technology, but it just sounded bad on its face," he told Reuters on Thursday.
