Allen Stanford has millions of dollars worth of assets on the Caribbean island of St. Croix, but U.S. regulators have not seized any in their probe of the Texas billionaire, a U.S. Marshal said on Monday.

James Sullivan, U.S. Marshal for the Virgin Islands, told Reuters that Stanford's assets here include a 120-foot yacht and a $7.7 million mansion in Christiansted, St. Croix's largest city.

The U.S. Securities and Exchange Commission charged Stanford, 58, last week with fraudulently selling $8 billion in certificates of deposit with improbably high interest rates from his Stanford International Bank Ltd (SIB), headquartered in Antigua. Regulators in Antigua have seized Stanford's banks and companies there.

In St. Croix, the largest of the U.S. Virgin Islands, investigators are compiling a list of Stanford's assets.

We know who owns the boat and home. If they (SEC) ask us to seize it we will, Sullivan said. As of today, we have no indications that they'll ask us...I don't know if they want us to or don't want us to.

Stanford did have corporate jets on the island, but Sullivan said he believed they have been returned to Stanford Financial's corporate hangar in Sugarland, Texas.

(Reporting by Martinne Geller; editing by Leslie Gevirtz)