She said: ‘We’re heading home’ the night she went missing

— which he said her family had taken from his home while he was in Cuba after Isabella went missing, scouring its hospitals for his wife.

According to police, as soon as Mr Bennett arrived, his sister-inlaw, elizabeth Rodriguez screamed at him to get out and ‘repeatedly stated that Lewis killed her sister’. Mr Bennett and the accompanying officer decided it was best not to pursue the matter and left empty-handed.

Other members of Ms hellmann’s family have revealed they became dubious about Mr Bennett’s account because of the unemotional way he reacted to the tragedy. Another of his sisters-inlaw, Dayana Rodriguez, recalled: ‘he was calm, he wasn’t crying or anything. When I saw him, I ran to him and I hugged him and I said: “Where is Isabella?” And he said: “I don’t know.” ’

She was dumbfounded by the way her brother-in-law, an experienced seaman, had reacted to his wife’s disappearance. When she asked him why he didn’t stop the boat and drop anchor, he told her ‘he needed to keep the boat on track’, she said.

‘I asked him: “Do you think she’s alive? Do you think she’s dead?” And he said: “I think she’s asleep.” That was his answer.’

She said her mother had ‘passed out on the floor’ when Mr Bennett had rejected their pleas to keep baby emelia in Florida, telling them: ‘I’m leaving and you’re not going to see the baby again.’

In June, weeks after Isabella hellmann’s disappearance, her oldest sister, Adriana Difeo, went to court in order to take over her sister’s finances from Mr Bennett. That case has yet to be settled. Asked about her sister’s death, Ms Difeo said yesterday: ‘We don’t know the truth yet. We’re waiting for the FBI report.’ For his part, Mr Bennett has insisted he is entirely innocent of any involvement in his wife’s death, and that it was ‘absolutely devastating’ to lose the ‘soulmate I had always searched for’.

Two months ago, in his first public formal comment since his wife’s disappearance, he wrote on Facebook that he had returned to Britain with his daughter ‘to seek the comfort of my friends and family’.

he added that he was taking ‘a time for reflection’ that he hoped might ‘lessen the negativity that I have encountered in this emotionally charged situation, and hope in the future a reconciliation will occur for all parties concerned, if not for my sake but for emelia’s’.

In recent years, he has preferred to travel far and wide. having studied at Bangor University in Wales, and then the Camborne School of Mines, part of exeter University, he moved to Australia, where he worked for several years in mining in Queensland before setting up a solar power business.

he met Isabella hellmann — who was living in Florida at the time — on the internet four years ago, although friends say he hardly ever went to visit her in America, instead having her fly out to meet him in places like Tahiti and Singapore, when he put into port on the yachts on which he was then working.

According to Sarah Cortes, a close friend at the Chase bank where Isabella used to work as a member of the counter staff, her relationship with the British engineer ‘started as a fling’ but soon became serious, and that she went to meet his parents at their home near Southampton. Ms hellmann told her friend that Bennett had come into some ‘family money’ and poured most of it into buying the catamaran, which he used to skipper for paying clients. hellmann’s baby, said Ms Cortes, was her ‘last shot at being a mother’.

Ms Cortes claims the couple didn’t have an easy relationship as parents, disagreeing over how to bring up their child.

Mr Bennett, she said, was a very hands-on father, and the couple argued over everything from whether to give the girl an english or Latino name to what sort of nappies she should wear, and whether to pierce her ears (a Colombian tradition which Mr Bennett hotly opposed).

More fundamentally, they were at odds over where they should live, according to Ms Cortes. Mr Bennett, she added, had been determined to move back to Australia, while his wife was equally set on staying in the U.S., said her friend.

Despite their differences, the couple were married in February in Atlanta, Georgia.

It was apparently an impulse decision, with Ms hellmann texting her shocked friend to say: ‘hey, I just got married.’

As for the last days of the fateful honeymoon cruise, nearly two weeks before she vanished, Isabella posted her last message on Facebook in Puerto Rico, saying simply: ‘Another day in paradise.’

her friend Sarah Cortes says Ms hellmann’s family received a final call from the missing woman at 8.30pm on the night she disappeared, to say they had had trouble with the boat’s satellite phone, but it was now fixed. ‘We’re heading home,’ she told them.

As for Mr Bennett, he does not seem to have been keen to hang around in America.

David Mayer, a neighbour of Bennett in Florida, recounted offering his condolences to him just two days after his wife’s disappearance. ‘he said: “Yeah. I’m going to be leaving for england. I’ve got to move on with my life,” ’ he recalled.

Isabella hellmann’s family clearly have their own views on what became of her, while her friends simply say they are holding out for a ‘miracle’. But more than three months after that mysterious night in the Caribbean, that seems less likely with every passing day.

Intriguingly, photographs taken at the time have now confirmed that there was a sizeable hole in the starboard hull of the catamaran.

But despite having attached a tracking beacon to the ship, the Coastguard lost track of it, and it’s presumed to have sunk into the depths of the ocean — perhaps taking with it any hope of finding out what became of Lewis Bennett’s wife.

‘I asked him, Do you think Isabella is alive?’