Isabella Hellmann disappeared from a private boat while on a honeymoon cruise with her husband. Photo / facebook.
The mysterious disappearance of a woman from a private boat while on a "honeymoon" cruise with her Australian husband is now the subject of an FBI probe.
Isabella Hellmann is presumed drowned in the Florida Keys, US after what her husband - former Gold Coast businessman Lewis Bennett - has told investigators was a terrible accident on board their boat 'Surf Into Summer', reports News.com.au The 40-year-old said he was jolted awake by a collision with an unknown object.
He had time to scramble to the deck and get into a lifeboat, but his Colombian-born wife was nowhere to be seen, reported The Australian.
The 11m catamaran has sunk in more than 40,000 feet of water and has not been found by the US Coast Guard. Neither has Ms Hellmann, despite a four-day search.
"We haven't had track of it or seen the boat since a beacon was attached weeks ago," Coast Guard spokesman Jonathan Lally told the Palm Beach Post this week.
Coast Guard divers were able to briefly inspect the boat before it was lost but couldn't determine what caused it to sink.
He has told authorities the couple left Havana at 5.30pm on May 14 and were at sea 100km off the Florida Keys when the "collision" occurred about 1am.
They had been married only three months and Ms Hellmann had told friends the week-long Caribbean trip was going to be a belated honeymoon, according to the Sun Sentinel.
"Caribbean, here I come," she posted on Facebook as they started the trip, before adding "another day in paradise" as they visited Puerto Rico.
The Post reported both the FBI and the Coast Guard had refused to comment on the nature of their investigations, other than they were looking into reports of a "missing person".
Neighbours however told the newspaper men wearing blue latex guards examined Mr Bennett's car while he was being questioned and the front door of the couple's home was sealed with a yellow FBI evidence tape.
It appeared Mr Bennett hadn't been home in several days. He holds dual Australian and British citizenship after becoming a citizen in 2013 and has lived on the Gold Coast where he had a company registered.
It's understood he wanted to bring Ms Hellmann and their baby daughter to live in Australia but she was unhappy about the prospect of living here.
A friend of Ms Hellmann told the Post there had been friction between the couple because of this. "She told me: 'I'm not going to Australia'," friend and former co-worker Lesmar Muller said
Now she is missing Ms Hellman's friends and family are fearful Mr Bennett would follow through on his plan and bring the child here.
"I begged him to please understand that the family lost Isabella and the only piece of Isabella left was [her child] and he needs to understand he just can't leave and take her," Sarah Cortes, who is Ms Hellmann's best friend, said. "He said he understands but he's got his life in Australia."
She said the couple argued frequently. The disagreements were mainly about how to bring up their daughter, from what she should eat to the sort of nappies she wore.
Mr Bennett was quoted by the Daily Mail as saying he could understand why the authorities were paying close attention to what happened.
"I have got nothing to hide ... I am not holding out much hope of seeing her so I have to come to terms with that. This is absolutely devastating for me.
"She is my soulmate. I thought we were going to be together forever. We were planning a great life together and now I am alone without her. I loved her very much."
They had been together since 2014.
The exact location of Mr Bennett and baby Emelia is unknown - but The Australian reports they are not thought to have come to Australia.
On May 28, nearly two weeks after Ms Hellmann was lost at sea, Mr Bennett is understood to have called local police and asked for their help in getting back belongings he claimed Ms Hellmann's family had taken from the couple's apartment.
"Someone has entered my property and taken some of my items. I believe it's my sister and mother-in-law," Mr Bennett told police on a recording made available to media.
"Eventually, Lewis and I decided that it was best that he leave," Boca Raton Officer J.P. Cohen wrote in publicly available documents.
It's believed Ms Hellmann's engagement ring and electronics and an expensive handbag were the items Mr Bennett said had been taken gone.
Ms Hellmann's frantic family have started a Facebook page about their search for her, begging people to keep sharing her picture and telling how they had been separated from Emelia.
"Isabella needs us! Share her photo and spread the voice. If we work together is easier to find her. Together for Isabella #FindIsabella," the page reads.
For now though all they can do is wait and hope to soon know what happened on-board the 'Surf Into Summer'.