(ST JOHN’S, Canada) — Debris recovered from the submersible that catastrophically imploded while on a voyage to see the Titanic wreckage last week contained “presumed human remains,” the U.S. Coast Guard said.

Salvaged pieces of the Titan vessel were unloaded from the Canadian ship Horizon Arctic at the Canadian Coast Guard pier in St. John’s, Newfoundland, Wednesday morning.

The U.S. Coast Guard said later Wednesday it has received the debris and evidence, including “presumed human remains,” that had been recovered from the ocean floor in the incident, in which five people died.

The evidence will be transported to a port in the U.S. for “further analysis and testing” by the Marine Board of Investigation, the Coast Guard said.

“The evidence will provide investigators from several international jurisdictions with critical insights into the cause of this tragedy,” Marine Board of Investigation Chair Capt. Jason Neubauer said in a statement. “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.”

The Marine Board of Investigation has been in contact with the families of those who were aboard the Titan, a source familiar with the situation told ABC News.

The development comes nearly a week after a remotely operated vehicle discovered remnants of the missing OceanGate submersible on the ocean floor. Debris, including the tail cone, was found about 1,600 feet from the bow of the wrecked Titanic on June 22, four days after the launch of the doomed tourist expedition.

Additional debris found was “consistent with the catastrophic loss of the pressure chamber,” according to Rear Adm. John Mauger, commander of the First Coast Guard District.

The Canadian Coast Guard said at the time it would remain on scene and “provide assistance and support to the recovery and salvage operations as requested by Maritime Rescue Coordination Centre in Boston.”

The U.S. Coast Guard is leading an investigation into the deadly incident, according to the National Transportation Safety Board, which said it will “contribute to their efforts.”

Additionally, the Royal Canadian Mounted Police said over the weekend that they are “examining the circumstances” of the deaths on board the Titan and will launch a full investigation if “the circumstances indicate criminal, federal or provincial laws may possibly have been broken.”

ABC News’ Luke Barr contributed to this report.

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