Investors who lost billions in a massive Ponzi scheme orchestrated by convicted former Texas tycoon R. Allen Stanford won a legal victory Monday as a federal appeals court decided to let their class action lawsuits go forward against individuals and companies they allege aided the financier's fraud.

The 5th U.S. Circuit Court of Appeals overturned a federal judge's ruling from last year that threw out three class action lawsuits that are trying to use state laws to recover investor losses resulting from Stanford's scheme.

U.S. District Judge David Godbey in Dallas had thrown out the lawsuits, saying they were precluded under the Securities Litigation Uniform Standards Act, or SLUSA, a federal act that says class action suits related to securities fraud cannot be filed under state law. Godbey had determined the fraud alleged by the lawsuits — filed by investors in Texas and Louisiana — was connected to the purchase or sale of securities such as stock.

But a three-judge panel of the appeals court disagreed with Godbey, saying "we find that the (alleged) fraudulent schemes ... are not more than tangentially related to the purchase or sale of covered securities and are therefore not sufficiently connected (to) purchases or sales to trigger SLUSA preclusion."