Texas billionaire Allen Stanford, accused of an $8 billion fraud that spooked investors around the world, was served with the formal complaint on Thursday by FBI agents in Virginia.

FBI spokesman Richard Kolko said the Federal Bureau of Investigation had acted at the request of the US Securities and Exchange Commission (SEC), and that Stanford had not been arrested. No criminal charges have been filed against him.

A law enforcement official said Stanford was making arrangements to surrender his passport. Stanford holds dual US-Antiguan citizenship, and has homes in the United States and the Caribbean.