U.S. prosecutors have announced the arrests of four men linked to a scandal involving an alleged campaign payment from Venezuela to Argentina. In Miami, VOA's Brian Wagner reports the governments of the South American nations have denounced the U.S. probe as a political attack by Washington.

From left: Former Argentinian President Nestor Kirchner,  President of Venezuela, Hugo Chavez and Argentina's new President Cristina Fernandez de Kirchner, 09 Dec 2007

Federal prosecutors announced Wednesday the arrests of three Venezuelans and a Uruguayan man accused of acting as undeclared agents of the Caracas government. U.S. authorities say the men came to Miami to pressure another man, Guido Alejandro Antonini Wilson, to conceal the fact that the money for a Venezuelan political campaign donation came from Venezuela's state oil company.

Antonini, who has American and Venezuelan citizenship, has been at the center of the scandal since he was caught in Argentina in August with a briefcase containing $800,000 in cash. He arrived in Miami shortly after the incident, and Argentina has asked for his extradition as part of an investigation into the money.

U.S. prosecutors say conversations between Antonini and some of the four men revealed that the money was intended for the presidential campaign of Cristina Fernandez de Kirchner.

Ms. Kirchner took over the presidency earlier this week, succeeding her husband, Nestor Kirchner.

In Buenos Aires, she denounced the accusations as an attempt to damage her new presidency.

President Kirchner said the attacks against her will fail, and that she may be a woman, but she will not allow others to pressure her.

She also vowed to maintain close ties with Venezuela's President Hugo Chavez, a fierce critic of U.S. policy in the region.

In Caracas, Venezuela's foreign minister, Nicolas Maduro, said the U.S. probe is an attempt to damage relations between Venezuela and its Latin American partners.

U.S. State Department spokesman Sean McCormack rejected allegations the operation was anything more than a criminal investigation.

"This is not an issue of U.S.-Argentine relations," said Sean McCormack. "This is a matter of U.S. law enforcement enforcing U.S. laws on U.S. soil."

The four men arrested in Miami face a fine and up to 10 years in prison if convicted on charges of acting as undeclared foreign agents.

Officials say they are looking for a fifth suspect in the case.

U.S. authorities have filed no charges against Antonini, whose attorney says he was unaware of the money in his luggage.