Obama administration's war on foreign tax havens is intensifying as investigators process a windfall of information about international bankers and their U.S. account holders.

Details gleamed from American taxpayers who came in from the cold to declare their secret offshore booty have already produced indictments.

South Florida criminal tax attorneys expect a number of international bankers to be charged for courting wealthy Americans to hide their capital in foreign shell companies that fed money to secret accounts in Switzerland, Liechtenstein and elsewhere.

"Without question they are looking at foreign bankers who came into the U.S. to meet with people, to accept deposits, to give them cash," said Martin Press, a criminal tax attorney and a Gunster partner in Fort Lauderdale, Fla. "They came in on tourist visas and met people around swimming pools wearing Hawaiian shirts to avoid detection."

Internal Revenue Service Commissioner Doug Shulman ended a speech in February announcing a new amnesty program with this thought:

"We have been getting better and better at detecting offshore accounts. Therefore, the risk of being caught is increasing," he said. "We now have a number of other banks under investigation based on information we received from our first round of disclosures and from other sources. Tax secrecy continues to erode."

Two foreign bankers have been charged this year in South Florida: Renzo Gadola and Christos Bagios, for activities at Switzerland's UBS. Four former Swiss bankers with Credit-Suisse were charged in Virginia in February.

Federal prosecutors would like these bankers to join Bradley Birkenfeld, who is serving a two-year prison term after blowing the whistle on his former employer, UBS, for hiding assets from the IRS for Americans. Unfortunately for Birkenfeld, he was not as forthcoming about a California billionaire client, which may have jeopardized millions of dollars due to come his way under a whistleblower law.

END GAME

The bigger question remains. What is the end game for the Justice Department and the IRS in the wake of the $780 million deferred prosecution agreement with UBS and high-profile prosecutions such as the Fort Lauderdale trial of Mauricio Cohen Assor and Leon Cohen Levy? The father-and-son developers were convicted of hiding $150 million in offshore accounts and sentenced to 10 years in prison.

A new landscape is in play. Centuries-old Swiss banking secrecy has been shattered, UBS surrendered the names of about 4,500 U.S. account holders, and 15,000 Americans chilled by IRS warnings have reported their secret accounts.

Attorney Jeffrey Neiman, who prosecuted Birkenfeld and the Cohens before going into private practice in Miami, said the mass taxpayer disclosures handed prosecutors information about the criminal wrongdoing of Swiss banks, big and small.

That could set up a frustrating cycle of indictments against bankers who can never be extradited, he said.

"Given this environment, I think it is inevitable that the United States and Switzerland will reach a global resolution resolving criminal exposure for Swiss banks and bankers," Neiman said. "It is anyone's guess whether this resolution would include a large fine, the disclosure of names, the closing of accounts or some combination of the three."

Under the voluntary disclosure program, taxpayers could avoid criminal prosecution, but they had to say what institution and banker helped them set up their accounts.

Miami tax defense attorney Robert Panoff said this information has been entered into a database that has generated substantial leads.

"The government has numerous pending investigations involving financial entities and individuals connected with those financial entities," he said.

Neiman said taxpayers could be called as witnesses against foreign bankers if prosecutors get ahold of them. "Calls are being made to attorneys who represent these taxpayers, asking for taxpayers to start producing records and sometimes being subjected to interviews by prosecutors and agents," he said.

STAYING ON THE SIDELINES

Will all this new information lead to another UBS-type showdown? Panoff doesn't think so.

He said banks got the message with UBS and the Cohens' trial last year. Unlike other tax haven defendants who reached plea deals, they presented their case to a jury, and their bank, HSBC, cooperated with prosecutors, providing taped conversations on efforts by Cohen Assor to hide assets in the Caribbean.

Some taxpayers with hidden accounts have decided to gamble and see if they get away with it. Others have allegedly tried to do an end-around the disclosure program by filing what are called quiet disclosures -- amended tax returns owning up to the hidden assets. They hope to avoid the 25 percent penalty on their highest undeclared foreign account balance and a 20 percent penalty on the taxes owed.

A second voluntary disclosure program has not brought in the record numbers of wayward taxpayers that the first program did, leaving the prospect of potentially prosecuting thousands.

"There are people still on the outside, saying 'I'm under the radar. I'm at a bank nobody has heard of. They are never going to get my name,'??" Neiman said. "I think those with offshore accounts need to know that the government does have at its disposal information at unprecedented levels on banks and bankers around the world who engage in this conduct."

Panoff added: "We are in the land of the recalcitrant now. That's what's left."

One recent case caught the attention of criminal tax defense attorneys. They said it showed that anything less than full disclosure won't be tolerated.

Michael Schiavo of Westford, Mass., was charged May 19 after he amended his tax returns to include some, but not all, offshore income from an HSBC account in Bermuda. Schiavo, a managing director at SCG Consulting Group, didn't partake in the voluntary disclosure program, instead making what is called a quiet disclosure.

"It was a clear shot fired over the bow," Panoff said.

It can be called the Birkenfeld rule. "You can't come partly in the door," Neiman said.

So how will the wealthy squirrel away money from the prying eyes of Uncle Sam now that European banks appear to be a closed door?

The Justice Department also is looking very hard at Israeli banks, sources said. Other banks also are of interest.

Josephine Bhasin of Huntington, N.Y., pleaded guilty in April to failing to disclose $8.3 million held in HSBC India.

While India is not usually thought of as a tax haven, a California federal judge in April granted a request by federal prosecutors to serve a "John Doe" summons on Indian banks seeking information on U.S. residents using accounts in India to evade U.S. tax obligations. The same type of summons was used against UBS in Miami federal court and helped bring the bank to the bargaining table.

Press said dual citizens also may try to deposit funds using a foreign passport to avoid new IRS reporting requirements that take effect in 2013.

"Whether people will apply for citizenship to another country to just avoid detection is certainly a possibility, but I would not recommend that," Press said.