Federal agents entered the Houston office of Stanford Financial Group on Tuesday, according to a Reuters eyewitness on the scene.
About 15 people, some wearing jackets identifying them as U.S. marshals, entered the lobby of Stanford's office in the Houston Galleria area, the eyewitness said.
Houston-based Stanford Financial Group, which says it oversees more than $50 billion of assets, is being investigated by U.S. regulators, according to a person familiar with the matter.
The New York Times reported that U.S. securities regulators had accused three top Stanford executives, including Robert Allen Stanford, of fraud.
The Houston office of the U.S. Marshals Service had no immediate comment. A Stanford spokesman was not immediately available to comment.
(Reporting by Anna Driver; editing by John Wallace)