In her first interview since the tragedy, Mrs Dawood said she had originally planned to explore the Titanic wreck with her husband, but the trip was cancelled because of Covid.

She then said she “stepped back” from the voyage to allow Suleman to take her place “because he really wanted to go.” Her comments contradict previous reports that the teenager was “terrified” before the trip but went anyway as a Father’s Day present.

She said she never wanted to hear the sentence “we lost comm” – signalling the submarine had lost communication with the outside world – ever again.

Asked what her last words were to her husband, who was one of Pakistan’s wealthiest businessmen, and her son, she said: “We just hugged and joked actually, because Shazada was so excited to go down he was like a little child.

“He had this ability of childlike excitement so they both were so excited.”

Suleman, she added, would not go anywhere without his Rubik’s Cube and even took it on board the vessel, in the hope of breaking a world record.

“He used to teach himself through YouTube, how to solve the Rubik’s Cube and he was really fast at it. I think his best was 12 seconds or something like that.”

It comes as the US Coast Guard ordered a far-reaching inquiry into the disaster which could lead to criminal and civil action being taken against those held responsible.

It has convened a Marine Board of Investigation (MBI) – the highest level of investigation conducted by the US Coast Guard.