More noises have been heard in the search for the missing Titanic sub. That’s according to the US Coast Guard.

Captain Jamie Frederick, who spoke with the BBC said that they still don’t know what the noises are but teams are still looking in that area. The search is also being expanded and the surface search is now twice the size of the US state of Connecticut, and the sub-surface search 2.5 miles deep

The crew are thought to have less than 20 hours of oxygen left, based on a previous estimate Contact with the sub – which has five people on board – was lost on Sunday as it made a 3,800m descent to the Titanic wreck.

Meanwhile, a former employee of OceanGate, the company that operates the missing Titan submersible warned of potential safety problems with the vessel as far back as 2018. According to US court documents David Lochridge, the company’s Director of Marine Operations had raised concerns in an inspection report.

It was stated in the report that there were: “numerous issues that posed serious safety concerns.” One of the concerns was the way the hull had been tested.

Mr Lochridge also stressed the potential danger to passengers of the Titan as the submersible reached extreme depths. He said his warnings were ignored and called a meeting with OceanGate bosses but was fired, according to the documents.