The US businessman is also a cricket promoter
The US financial authorities say they do not know the whereabouts of Sir Allen Stanford, the Texan billionaire accused of an $8bn (£5.6bn) fraud.
He has not been seen since Tuesday, when the Securities and Exchange Commission filed a civil case in court.
The SEC said Sir Allen and two other executives promised clients unrealistic returns on certificates of deposit.
Depositors in the US, the Caribbean and South America have queued to withdraw money from banks associated with him.
No criminal charges have yet been made.
In an e-mail to his employees last week, Sir Allen promised to help the SEC probe and vowed to "fight with every breath to continue to uphold our good name and continue the legacy we have built together".
The 58-year-old, who holds joint US-Antiguan citizenship, is a flamboyant figure who has links with prominent US politicians and sports stars.
He is the biggest private-sector employer on Antigua and Barbuda.
A civil court judge in the US has frozen the assets of Sir Allen and the other accused as well as those of the Stanford Group, its Antigua-based subsidiary Stanford International Bank (SIB), and another subsidiary, investment adviser Stanford Capital Management.
The BBC's Greg Wood, in Houston, said a steady flow of people had turned up at the Stanford group's headquarters in the city on Wednesday, trying find out what had happened to their money.
One Houston estate agent and financial adviser, Michael Harrington, told the BBC that he had been encouraging his clients to invest with the Stanford group, and he feared some would have lost a lot of money.
"The greed in this line of work has just gotten to an extreme that we're not comfortable with referring anyone to almost anyone in this industry," he said.
Hundreds of investors throughout the Caribbean and South America also gathered at branches of Stanford International Bank and its affiliates.
The Associated Press reported that they left empty-handed, being told that their accounts were frozen.
In an effort to protect investors, Colombia and Ecuador suspended the activities of some Stanford affiliates, Panamanian regulators occupied Stanford bank branches hit by a run on deposits, and Mexico and Venezuela were also said to be considering measures.
Hundreds of depositors of Sir Allen's Bank of Antigua in Antigua also sought to withdraw their funds on Wednesday, although the bank is separate from SIB.
The SEC said no-one but Sir Allen and James Davis, SIB's chief financial officer, knew where most of cash has been invested and accused both men of failing to co-operate with investigators.
Filing a case in the civil courts against Sir Allen, the SEC described the case as "fraud of shocking magnitude that has spread its tentacles throughout the world".
Sir Allen, a leading figure in the cricket world, last year promoted the Stanford cricket series which saw a West Indian all-star team - the Stanford Superstars - beat an England team for a $20m prize.
The England and Wales Cricket Board (ECB), which has a five-year deal to play games against the Stanford Superstars, suspended sponsorship negotiations with him following the SEC's move against Sir Allen.