FBI agents served the complaint from the U.S. Securities and Exchange Commission on Texas billionaire Allen Stanford in Fredricksburg, Virginia, an FBI spokesman said on Thursday.
FBI spokesman Richard Kolko said the FBI acted at the request of the SEC and that Stanford had not been arrested. He has not been charged with any crime.
The complaint, accusing Stanford of an $8 billion fraud, was served on him by agents from the FBI's office in Richmond, Virginia. Kolko said.
Stanford is accused of cheating some 50,000 customers out of $8 billion dollars. Thursday's action comes after raids Tuesday of his financial empire in Houston, Memphis, and Tupelo, Mississippi.
Stanford and three of his companies were charged with fraud in a civil complaint filed in federal court in Dallas, Texas.
The Securities Exchange Commission alleges Stanford ran a fraud promising investors impossible returns, much like Bernard Madoff's $50 billion alleged Ponzi scheme.
The fallout from Stanford's dealings are felt overseas. Authorities in five Latin American countries have taken action against Stanford businesses.
Venezuela seized a local bank owned by Allen Stanford on Thursday to stem massive online deposit withdrawals as the impact the U.S. fraud case against the Texan billionaire spread through Latin America.
The government of President Hugo Chavez said it would quickly sell the bank —Stanford Bank Venezuela, one of the country's smallest commercial banks—and that it had already been approached by potential buyers.
In recent days, depositors at the bank had worried over the fraud case targeting a sister company, Stanford International Bank, even though the companies' assets are separate.
Depositors withdrew cash using Internet banking services. The bank takes deposits and makes loans only in the OPEC nation's local currency.