OceanGate's CEO told a passenger "very strange things" when he boarded the Titan submarine which imploded last month - including the three chilling words of "you're dead anyway".
Brian Weed, a documentary cameraman, went on a test dive in the doomed vessel in May 2021 while working for the Discovery Channel's "Expedition Unknown" TV show.
But when he boarded the sub he recalled having a "very strange" conversation with boss Stockton Rush after asking him about the safety of the sub.
However, Mr Rush appeared to dismiss any concerns over safety as the passenger admitted he felt "uneasy" with his "cavalier" attitude.
He said: "Well, there's four or five days of oxygen on board, and I said, 'What if they don't find you?' And he said, 'Well, you're dead anyway.
"It felt like a very strange thing to think, and it seemed to almost be a nihilistic attitude toward life or death out in the middle of the ocean."
Mr Weed revealed the test dive was riddled with mechanical and communications issues and had to be aborted.
"That whole dive made me very uncomfortable with the idea of going down to Titanic depths in that submersible," Mr Weed said, adding that it just didn't feel safe.
He pulled out of the documentary amid concerns over safety, and the 'Expedition Unknown' production was also later cancelled by the channel.
OceanGate had been previously warned by ex-staff members of the safety of the submarine after it was revealed its carbon fibre hull, which housed the five passengers, was its "Achilles heel" because the material is not considered suitable for deep-dives.
The company's CEO Stockton Rush said in 2021 the carbon fibre broke a "rule" by not allegedly being certified to carry passengers to the depths of the Titanic.
He said in an interview: "The carbon fibre and titanium, there's a rule you don't do that – well I did."
Stockton Rush, Shahzada Dawood, his son Suleman, British billionaire Hamish Harding, and French explorer Paul-Henry Nargeolet all died aboard the sub, which imploded while on a trip to visit the Titanic wreckage after less than two hours into its dive.
The trip, which costs around $250,000, allowed tourists to see the shipwreck up close.
However, the vessel lost communication with its operator and a large-scale rescue operation was deployed to search the area 400 miles southeast of Newfoundland, Canada, as oxygen supplies in the submarine had just days left.
However, a debris field was found by the Coast Guard around 1,600 feet from the bow of the Titanic last week.
"Presumed human remains" and debris from the submarine were unloaded from the US Coast Guard ship Sycamore and Horizon Arctic at the Canadian Coast Guard pier in St John's, Newfoundland.