Human remains have likely been recovered from the wreckage of the submersible that imploded during an underwater voyage to view the Titanic, the US Coast Guard said Wednesday.

The news came hours after the announcement that debris from the Titan, collected from the seafloor more than 3,658 metres below the surface of the North Atlantic, had arrived in St John’s, Newfoundland.

Twisted chunks of the submersible were unloaded at a Canadian Coast Guard pier.

Recovering and scrutinising the wreckage is a key part of the investigation into why the Titan imploded last week, killing all five people on board.

The multiday search and eventual recovery of debris from the 6.7-metre vessel captured the world’s attention.

“There is still a substantial amount of work to be done to understand the factors that led to the catastrophic loss of the Titan and help ensure a similar tragedy does not occur again,” Coast Guard Chief Captain Jason Neubauer said in a statement released late Wednesday afternoon.

The company charged passengers $250,000 each to participate in the voyage.

The implosion of the Titan has raised questions about the safety of private undersea exploration operations.

The Coast Guard wants to use the investigation to improve the safety of submersibles.