Updated | Five dead as Titan submersible suffered 'catastrophic implosion'

Updated at 8:00am 23 June

Five passengers onboard the Titan submersible that went missing on Sunday in the Atlantic Ocean died after the vessel suffered a "catastrophic implosion", the US Coast Guard said.

The conclusion was reached after a remotely operated vehicle scouring the seabed found debris some 480m away from the wreck of the Titanic on Thursday afternoon. The wreckage contained pieces that belonged to the submarine.

The likeliness is that the submarine imploded at the same time that all communication was lost on Sunday, almost two hours into the dive. The debris was found in the water column where the last contact with the submarine was registered.

Meanwhile, it has emerged that the a Cold War era spy system to detect submarines operated by the US Navy had picked up noise consistent with a catastrohpic implosion on Sunday at around the same time the submarine lost contact.

The US Coast Guard said that metal banging noises picked up by sonar buoys on Tuesday and Wednesday, originally believed to have been coming from the missing submarine, could have been coming from other ships in the area. "In the past 72 hours we've had sonar buoys in the area and any implosion would have been picked up," the US Coast Guard said, implying that the submarine could have met its catastrophic end on Sunday.

The debris discovered on Thursday included a landing frame and a rear cover from the submersible. The porthole window was also found.

The dead people are pilot Stockton Rush, the CEO of the company leading the expedition. His passengers were a British adventurer, Hamish Harding, two members of a Pakistani business family, Shahzada and Suleman Dawood, and a Titanic expert, Paul-Henry Nargeolet. OceanGate Expeditions oversaw the mission. Shahzada Dawood is also a Maltese citizen after he bought a golden passport.