The US government has moved to seize property that belonged to ousted Florida law firm chairman Scott Rothstein, who is being investigated for allegedly running a Ponzi scheme that investors say cost them $500 million or more, according to an article in Law.com.

Authorities have taken over a chunk of Gibraltar Private Bank & Trust stock and cars that Mr Rothstein owned or gave as gifts to his former law partners, the report said.

The investigation comes at a time when the recent financial crisis has revealed a number of actual or alleged frauds, some of them Ponzi schemes, although by far the largest such scam to have come to light is the $65 billion fraud of Bernard Madoff, now serving a 150-year jail sentence.

FBI and Internal Revenue Service agents spent much of Monday taking inventory at Mr Rothstein's $6.4 million Fort Lauderdale home, where several of his luxury cars and boats were kept. News photographers captured images of a Ferrari being towed away. Rothstein faces no criminal charges, but assets typically are seized in fraud investigations to be available for sale later to repay wronged investors, the  report said.

Mr Rosenfeldt declined to comment, it added.

Gibraltar Private Bank & Trust said Monday it received a federal warrant to seize an interest in the company tied to Mr Rothstein.

The Coral Gables, Fla.-based private bank and wealth management firm said a firm linked to Rothstein was one of the investors when Boston Private Financial Holdings sold Gibraltar to private investors for $93 million in September.