Fjellhoy, a 29-year-old Norwegian masters student living in London, said she was swept off her feet on their first date, which included a private plane ride to Bulgaria. Fjellhoy said Leviev told her he was an Israeli millionaire who called himself the "Prince of Diamonds."
"I was texting my friends at the same time like in a group chat just like, 'I don't know what's going on,'" she said.
But what began as a storybook romance turned into a real-life nightmare, Fjellhoy said – one that sent her into debt and fearing for her safety. It's a cautionary tale in the dangers of online dating.
"I hate him, he's so horrible," she said. "I am just tired of crying about this you know? It's just so painful. I just hate myself that I did this."
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Leviev was born Shimon Hayut, a 28-year-old convicted Israeli con-man who served three years in Finnish prison for defrauding several women in order to fund his lavish lifestyle of private jets and fast cars, which Fjellhoy said he loved to show off.
Fjellhoy said Hayut defrauded her out of more than $200,000, finding herself lulled into a false sense of security by his grand romantic gestures and flowery declarations of love. She said she fell prey to "confidence fraud."
In June, Hayut was arrested in Greece for using a false passport following a joint operation between Interpol and Israeli police.
Outside of court Hayut told reporters from VG, a Norwegian outlet that first broke the story, "I will go back to Israel, [which] is my home country, and I will face what is waiting for me there and that's it, and we will sort everything out. [Whatever] problems that we have, we will sort it out in court."
He now faces extradition to Israel, where he was indicted in 2011 on theft, forgery and fraud charges unrelated to Fjellhoy but he fled the country before he was set to stand trial.
According to the U.S. Federal Trade Commission, internet-facilitated romance scams, also known as confidence fraud, is the number one type of consumer fraud in the U.S. Around the world, victims of confidence fraud lose billions of dollars each year, according to the FBI.
Fjellhoy, who shared her story with “Nightline” earlier this year, said her romance with Hayut started out innocently enough.
"This was the first time where I felt like, 'Oh my god I really like him. And it seems that he really likes me back as well,'" She said. "He's texting and he's calling and he seems to really want to get to know me, and I think I feel a bit for that."
Fjellhoy said Hayut told her that his job as a diamond dealer, working for a company called LLD Diamonds, kept him traveling constantly, so they dated long distance. She said they sent each other love notes over text, in video declarations and voice recordings.
She said he came to visit her in London when he could, but more often than not, she said he flew her to where he was. She said he would always allude to an element of danger in his job that kept him away, always on a private jet. At one point, Fjellhoy said he told her he couldn't go back to London because of threats he was receiving, "but he could get me to where he was."
She said Hayut claimed to be under constant threat from unknown nefarious enemies. She said he told her it was a hazard of working in the diamond business.
Fjellhoy said Hayut surrounded himself with people who helped perpetuate the myth, even going so far as to send photos of himself and his bodyguard in the hospital after they were allegedly "attacked."
According to Fjellhoy, it was not long before Hayut made a big ask, begging her to extend her line of credit to him so that any plane tickets, hotels and dinners would be booked under her name and his supposed "enemies," as she said he called them, would be thrown off his trail.
"One of the main reasons why he needed it was protection… he needed my name as a cover, he said," Fjellhoy told "Nightline." "I know it sounds crazy... [but] why would he have this giant guy with him if he didn't need the protection?"
Fjellhoy said she relented because Hayut promised to pay her back, but funding his jet-set lifestyle was costing her. And the money he was promising her wasn't coming in.
"My angel My love I just talked to the bank and they told me that the [transfer] of Amex will be there on Monday thousand percent," read one text message Hayut sent her.
"The amount that he needs to be able to just function for a week is just so much," Fjellhoy said. "It's never just a few thousand, for us normal people that is a lot of money, but for him it's not a lot of money."
She said he told her he needed large amounts of money because he had "an entire team" he needed to book flights and hotels for. Fjellhoy said she assumed, due to his flashy clothes and lifestyle, he had money and would pay her back.
"You didn't even think that it was a problem when you were taking up the loans because you were so sure that this guy and the people that you had met was part of the LLD Diamonds and that the money existed," she said. "When he said, 'Everything's going to be fine after this week,' and then it didn't. So just 'one more week' and then 'one more week.' So in the end you almost you didn't even realize how much money you actually [owed]."
And ultimately, Fjelljoy said, she was in love with him.
"That's the hardest part of it … when I realized that he wasn't [who] he said he was," she said. "That the person that I thought that I knew and loved, he had just done [something] in the most evil way."
The moment she realized that the man she loved had taken the money and run was "such a shock," she said.
"I almost wanted to throw up," she said. "It was the first time in my life that I had gotten such a shock that my body physically was telling me that, 'OK your life is ruined,' everything came crashing down around me."
Fjellhoy alleged that Hayut continued to run the same scheme to lure other women into his orbit until his June arrest.
"I had to be put into a hospital. Psychiatric ward. Because of suicidal thoughts because I thought my life was over, like I didn't see a way out," she said. "You've lost your boyfriend but he didn't just dump you, he never existed, he was never your boyfriend."
Fjellhoy filed a report with the Metro Police in London, who declined "Nightline's" request for comment. Israeli authorities also declined to comment for this report.
Hayut told "Nightline" in May that he was innocent. In a text message, he said, "There is nothing here just [a] loan between friends that went south… she agreed to loan me the money and then she disappeared… before we [were]able to pay back… they used me for my life they got expensive gifts and everything, In other words gold diggers, When I ask help they agreed to help and they know that I have some problems I didn’t run from no one it's all fake news and lies."
For now, Fjellhoy remains in London and is trying to rebuild her life. She told “Nightline” via text that the news of Hayut's arrest was “really amazing” and that she believes the media attention was an important factor in leading to his capture.