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.