Romanov was apprehended by Russian criminal investigation officers in Moscow on Monday.
An international arrest warrant was issued for the former owner of Ukio Bankas in 2013, on charges of embezzlement.
It was claimed Romanov had fabricated a health scare in order to leave Lithuania and escape prosecution.
Lithuanian authorities claimed they had no idea where Romanov was and insisted they were unable to act on reports the 66-year-old was in Moscow.
A Russian reporter told Lithuanian TV last year that Romanov was in Moscow, and revealed that it was 'some kind of story' that he had been suffering from poor health.
And released documents showed that Romanov had transferred around £12m from one of his accounts into his own Ukio Bankas at the time Hearts' problems began. The funds poured into Ukio Bankas were used to increase the bank's capital.
Embezzlement charges arose after papers from the Bank of Lithuania showed he had paid the money to himself.