Authorities in five Latin American nations have now taken action against Stanford businesses, with Ecuador seizing two local branches of the group on Thursday, the Reuters news agency reported.
The US Securities and Exchange Commission (SEC) raided Stanford's Houston offices on Tuesday and filed civil fraud charges against him and two of his executives, accusing him of fraudulently selling $8 billion in certificates of deposit with impossibly high interest rates to investors across the world.
The SEC also froze Stanford's assets and those of three of his companies, Stanford International Bank, based in Antigua, and Stanford Group and Stanford Capital Management, both based in Houston.
Depositors across Latin America and the Caribbean have since rushed to withdraw savings from Stanford-controlled banks.
The current whereabouts of Stanford, a billionaire from Texas, remain unknown, authorities say.
Regulators allege Stanford forged historical data about investments which he then used to lure more investors for his products.
On Wednesday in the twin-island state of Antigua and Barbuda where Stanford is the biggest private employer, Baldwin Spencer, the prime minister, said the SEC charges could have "catastrophic" consequences, but urged the public not to panic.
But in Antigua's capital, St John's, the Venezuelan capital, Caracas, Mexico City and other cities hundreds lined up outside Stanford banks and offices to withdraw funds.
Stanford, 58, is one of the most prominent businessmen in the Caribbean, with a personal fortune estimated at $2.2bn by Forbes magazine.
The charges are the latest to be brought after an increase in scrutiny by investors, politicians and regulators on the returns promised and provided by investment firms, following the massive alleged $50bn fraud by Bernard Madoff, the Wall Street financier.