Canadian police are looking into the deaths of five people killed in the implosion of the Titan submersible.
Superintendent Kent Osmond, of the Royal Canadian Mounted Police, confirmed on Saturday it was looking into the circumstances.
Parts from the sub were discovered on the sea floor on Thursday, only about 400m from the wreck of the Titanic.
The US Coast Guard said the vessel had suffered a catastrophic implosion which would have killed all those on board.
Canadian police appear to be leading the criminal investigation because the ship towing the sub left from Newfoundland and was a Canadian-flagged vessel.
It has emerged that a number of engineering and deep sea experts, including a former employee, had raised serious concerns over the sub’s safety with the company’s boss
However, Stockton Rush – who also died in the incident – is said to have dismissed the concerns.
Many of them focussed on the novel carbon fibre design used for the hull and the fact the submersible had not been certified by outside agencies.
TV and and film makers – including the UK’s Ross Kemp – have since revealed they declined the chance to travel in the sub due to fears over its capability.
Three British citizens and a French Titanic expert died alongside Mr Rush after paying hundreds of thousands of pounds to see the famous wreck.
The Titan sub lost contact less than two hours after its descent last Sunday.
Latest tributes to the victims were paid today by the sons of billionaire private jet dealer Hamish Harding.
One of them described him as the “best father I could have ever asked for [who] inspired me more than anyone will ever know”.
As well as the police probe, Canadian safety officials have announced their own investigation.
The Transportation Safety Board (TSB) said on Friday that it had sent a team to St John’s in Newfoundland to gather information and interview people.