A prominent Georgia Republican was running a Ponzi scheme that defrauded 300 investors of at least $140 million, federal officials alleged in a complaint filed Thursday. The civil lawsuit by the U.S. Securities and Exchange Commission said First Liberty Building and Loan, controlled by Brant Frost IV, lied to investors about its business of making high-interest loans to companies. Frost is alleged to have taken more than $19 million of investor funds for himself, his family and affiliated companies even as the business was going broke, spending $160,000 on jewelry and $335,000 with a rare coin dealer.