It's also unknown for how long the credit union was processing $30 million a month. Helping Other People Excel FCU was liquidated by the federal agency last month.

Nevertheless, Heinz E. Ickert, a forensic accountant and investigator in Columbus, Ohio, said this criminal enterprise was a sophisticated scheme with very intelligent criminals who treated their venture as a true business and paid close attention to every detail.

"It is rare to find a fraudster who takes such care and goes to the lengths these defendants did to avoid detection and keep the scheme going," Ickert told CU Times. "Very few fraudsters go to this length, but the dollars involved warrant their efforts. These 'professionals' did their best to cover up the schemes, invested in their 'business' to make everything look legitimate, and apparently were very cautious and diligent."

Indeed, the fraud case captured national media attention because the criminal enterprise was allegedly responsible for the largest customer data theft case in history involving the nation's biggest bank. That news, which publicly surfaced during the summer of 2014, caught the attention of federal authorities who launched an investigation.

From 2012 to mid-2015, the leader of the criminal enterprise, Gery Shalon, allegedly orchestrated massive computer hacking crimes against seven U.S. financial institutions, including JPMorgan Chase Bank, national investment brokers Scott Trade and E*Trade, and the Dow Jones & Co, the parent company of the Wall Street Journal. The other financial institutions were not identified in court documents.

Federal prosecutors said personal information belonging to more than 100 million customers from these financial institutions was stolen. Of that total, JP Morgan Chase accounts for 76 million households and seven million small businesses were compromised.

In addition to owning unlawful Internet gambling businesses in the U.S. and abroad, as well as multinational payment processors for illegal pharmaceutical suppliers, counterfeit and malicious software distributors, and unlawful Internet casinos, Shalon also owned Coin.mx, an unlicensed Internet Bitcoin exchange service that allegedly laundered money for criminals.

According to recently released court documents, Shalon's criminal enterprise processed hundreds of millions of dollars in transactions, earning a percentage of every transaction, which amounted to more than $18 million in illicit profits.

Shalon and his co-conspirators routinely lied to financial institutions about the true nature of their businesses and even colluded with corrupt international bankers who looked the other way for profits, according to prosecutors.

Court documents also revealed U.S. credit card companies repeatedly identified bank accounts that received illicit payments and imposed millions of dollars in penalties on their respective financial institutions.

However, Shalon and Orenstein, according to prosecutors, paid millions of dollars to the financial institutions to cover those penalties.

To avoid further financial penalties and processing shutdowns, as well as to evade law enforcement detection, the criminal enterprise worked continuously to obtain new bank accounts and establish fake merchants to replace those that were periodically shut down by banks and credit card companies.

What's more, Shalon and his co-conspirators managed to hack into the servers of a U.S.-based company, which assessed merchant risk and compliance for credit card issuers. According to prosecutors, Shalon and others monitored the U.S. company's detection efforts, which included reading employee emails so Shalon could avoid being caught.

Earlier this month, Lebedev pleaded not guilty to conspiracy in Manhattan's U.S. District Court to bribing a senior executive of Helping Other People Excel FCU.

Federal prosecutors alleged Lebedev and others participated in a bribery scheme to gain control of the credit union in order to conceal the operations of Coin.mx.

The credit union executive was allegedly bribed with more than $175,000, according to court documents. When contacted by CU Times last week, federal prosecutors declined to comment on whether the executive would face charges.

According to court documents, Murgio managed Coin.mx and allegedly participated in bribing the senior executive, who was not identified.