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.

According to local real estate brokers who worked with Stanford and his associates, the flamboyant financier also owns several other pieces of residential and commercial real estate including a $9 million hilltop estate and $5 million worth of storefront property in downtown Christiansted.

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 (the 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 Sugar Land, Texas.

Stanford purchased the downtown mansion, known as the Bjerget House, last year at an auction related to the bankruptcy of its former owner, Jeffrey Prosser and his Innovative Communication Corp.

The sprawling 18th century home was once owned by the Danish pianist and comedian Victor Borge and its opulent, gated exterior is a sharp contrast to its smaller Hill Street neighbors.

(Reporting by Martinne Geller; editing by Leslie Gevirtz and Tim Dobbyn)