WASHINGTON, Aug. 22 — Federal officials have developed a plan to seize financial assets laundered into the United States by foreign leaders whom they suspect of public corruption, with a jailed former president of Nicaragua as the first target.

Federal agents at a newly created multiagency task force in Miami have opened nine investigations into allegations of foreign money laundering in six Latin American countries, officials said. In at least one case, a high-ranking foreign official is under investigation, they said.

An inquiry involves ex-President Arnoldo Alemán of Nicaragua. Photo Associated Press

The effort reflects an aggressive new strategy to try to trace "dirty" money in the United States to its foreign roots, in part by using expanded powers granted to the government under the USA Patriot Act, as the sweeping legislation passed after the Sept. 11 attacks is known, officials said.

The highest-profile target is Arnoldo Alemán, the former president of Nicaragua, who is imprisoned there on charges of embezzling $100 million before he left office in 2001. Agents in Miami in recent months have seized about $5 million in Florida bank accounts and real estate holdings that they believe was laundered by the former president, his family and associates.

Law enforcement officials who spoke on condition of anonymity said they were also considering bringing criminal money-laundering charges against Mr. Alemán. Although Nicaragua has assisted the United States in its investigation, a move to indict the former president could set off a diplomatic showdown with Nicaragua because officials there have indicated they would not extradite Mr. Alemán. His family and supporters have denied wrongdoing.

In a second case, the Miami task force is investigating a widening scandal in the Dominican Republic over allegations that banking officials embezzled hundreds of millions of dollars and gave lavish gifts and payments to government officials. United States officials said that they believed they could trace some of the money to Florida holdings, and that they expected to seize assets there in connection with the investigation.

While several investigations involve officials who have fallen out of power, the task force is also pursuing accusations of laundering and white-collar crime against a high-ranking official who is in office in an undisclosed Latin American country, officials who spoke on condition of anonymity said. It is unusual for the United States to open a criminal investigation into a sitting foreign official, and United States officials refused to identify the official, citing the diplomatic sensitivity of the case.

Charles A. Intriago, a former prosecutor who runs the Web site ( www.moneylaundering.com ) and has published periodicals on the issue, said the push to investigate American ties to foreign corruption "is a major development, and it's long overdue" after years of sporadic attention.

South Florida in particular has been a popular haven for deposed leaders from Latin America and their assets. Banks with bilingual staffs have flourished in Miami and elsewhere thanks to large infusions from foreign political and business leaders who seek stable investments.

"Sometimes we've tended to coddle foreign dictators," Mr. Intriago said, "but focusing attention on foreign corruption is an indispensable part of attacking worldwide crimes like drug trafficking, terrorism and arms trafficking."

Agents in Miami have relied in part on expanded financial powers granted to them under the USA Patriot Act. Little-noticed provisions have given the government authority to seize foreign bank accounts in the United States in money-laundering cases and to pursue embezzlement and fraud cases overseas that previously might have been considered off limits to investigators.

Money laundered into American financial institutions by corrupt foreign leaders totals as much as $2 billion by some estimates, as they "park" their money in American banks, real estate holdings, securities and even insurance policies. Federal officials said a growing recognition of the problem has prompted them to develop a broad-based approach to attack the problem.

We have indications that it's not uncommon for corrupt leaders in foreign countries to put their money in United States banks and institutions," said John Clark, the interim director of the Department of Homeland Security's Bureau of Immigration and Customs Enforcement, which is leading the task force.

"What we're trying to do is send a message to criminals overseas: don't come here," Mr. Clark said.

Officials in the Department of Homeland Security gave the final approval last week for the creation of a pilot operation in Miami that will bring together federal agents and prosecutors from different agencies to track laundered money from foreign government leaders, to seize assets tied to corruption, and to prosecute foreign leaders. The departments of Justice, State and Treasury are all involved in the task force, which has been working informally for several months.

Federal authorities said the move was the first time that they had adopted such a coordinated approach to tracing the money of corrupt foreign leaders. In the past, officials said, instances of suspected money laundering by foreign leaders were investigated on a piecemeal, case-by-case basis, if at all.

All of the current investigations focus on Latin American nations, but officials would not identify the countries other than Nicaragua and the Dominican Republic.

Officials said they hoped to expand the targets to other global regions through similar operations in American financial centers like New York, Los Angeles and San Francisco.

The push also reflects the realities of Washington turf struggles: customs and immigration officials in the Department of Homeland Security, after frequent bouts with the F.B.I. over control of terrorist financing cases, were losers in a recent interagency agreement that gave the F.B.I. lead control over terrorism cases. As a result, those agencies have sought to expand their niches in other areas of financial crimes.

In cases likes Nicaragua, officials said they planned to return any money seized to the country from which they believe it was taken. But they said the United States stands to gain as well.

"If we can assist a foreign government to remain stable," said one official involved in the project, "then we'll do it. The last thing we want is corrupt government officials destabilizing a foreign government and creating a financial vacuum that could affect the United States."

Copyright 2003 The New York Times Company. Reprinted from The New York Times, National, of Saturday 23, 2003.