Mr. Byrne, whose father had been the chief executive of the insurance company Geico, has a reputation for speaking his mind with financial analysts and in interviews. The news release on Monday was particularly colorful and, at times, cryptic.
It did not mention Ms. Butina specifically, but instead cited two articles published recently on the website of Sara Carter, a journalist and Fox News contributor. One of the articles detailed his relationship with Ms. Butina. In the news release, Mr. Byrne said that he “confirmed” Ms. Carter’s account.
The relationship, Mr. Byrne said in the interview, began in Las Vegas, where he was giving a talk at the FreedomFest convention, an annual gathering of libertarians.
Ms. Butina, according to Mr. Bryne, introduced herself and said that she wanted to discuss her gun rights group, but that he was not interested. She then told a different story: that she was working for a top official at Russia’s central bank and wanted Mr. Byrne to come to Moscow to speak about blockchain technology. Mr. Byrne arranged to meet her for lunch in his hotel suite the next day.
They hit it off, he said, discussing Russian history, literature and philosophy. “She said you are a very famous man in Russia,” he recalled.
Still, Mr. Byrne described being somewhat suspicious of Ms. Butina’s intentions. Eventually, he said that he began to communicate with the F.B.I. about their interactions. Mr. Driscoll, Ms. Butina’s lawyer, said that Mr. Byrne had contacted him after she was sentenced to prison in April and had told him he had spoken periodically to the F.B.I. about Ms. Butina. An F.B.I. spokeswoman declined to comment.
After the convention, Mr. Byrne and Ms. Butina kept in touch through text messages. She told him she wanted him to meet her in Paris, Rome or Montenegro. They finally decided to meet at the Bowery Hotel in New York in September 2015. Mr. Byrne, who calls himself as a “56-year-old bachelor,’’ said that the rendezvous in New York quickly became romantic. They met several more times in different cities around the United States, and she visited him at his home in Utah.