The U.S. attorney’s office has said it has no evidence that the Cuban government of Fidel and Raul Castro played a role in the alleged scheme to launder fraudulent Medicare proceeds. Cuban officials bristled at the allegation, denying any involvement.

But The Miami Herald has learned that the laundered millions were automatically wired from the shell companies’ dozen-plus accounts at Trinidad’s Republic Bank branch in Havana into Cuba’s state-controlled bank. Publicly, federal court documents have only said that “at least two of those accounts had standing instructions to the bank to wire all money immediately from the accounts to the Cuban banking system.”

Cuba’s national bank is broken down into several banks with different specialties, offering commercial, consumer, trade, tourism, foreign exchange and services.

Despite the variety of banks, “there really is just one owner, the government of Cuba,” said Fernando Capablanca, a former Miami banking executive and now a banking consultant.

The Trinidad bank, which opened a Havana office in May 2002, has turned over records of the various shell companies’ transactions to the FBI, but publicly the institution has only said that it had no relationship with Sánchez, the defendant.

Trinidad and Tobago Attorney General Anand Ramlogan declined to comment on the Sánchez case, saying he doesn’t know all of the facts. However, he said, the country has taken a number of steps to combat money laundering.

“We do have ‘Know Your Customer’ laws,” Ramlogan told The Miami Herald at his office in Port-of-Spain. “We do have source of funds declarations. There are things in place.”

Sánchez was able to stay under the radar because he went to great lengths to disguise himself and the true source of the laundered funds by never putting his name on any corporate or bank documents, authorities say. He incorporated his Naples check-cashing company, Estates Business Center, in his wife’s name, Ilens R. Sánchez.

Oscar Sánchez, who came to the United States in the 1980 Mariel boatlift, struggled as a new immigrant and developed a record as a petty criminal in Florida. He finally prospered in the mid 2000s when he allegedly joined the Medicare rackets as an unofficial banker and later began investing in real estate in the Naples and Fort Myers area.

Despite attempts to cloak himself in secrecy, authorities say, Sánchez made at least one fatal mistake that they consider a “smoking gun.” In February 2007, he transferred $38,357 from his personal Florida bank account into the account of a Canadian company called Magnus Aviation Logistics. The Montreal company was at the center of the alleged cash-to-Cuba laundering network, according to at least one healthcare fraud case related to the Sánchez indictment.

Sánchez was described by federal prosecutor Ron Davidson as a “financier for fraudsters and a capitalist for Cuban banks,” who had made 78 overseas trips during the past decade, according to a motion to detain him before trial. Of those, 61 trips were made to Cancun, Mexico, a jumping off point for Cuba. His fellow passenger on one Cancun flight: the owner of several “fraudulent” Miami-Dade healthcare companies that wired money to Cuba, through Canada and Trinidad, court records show.