A former financial adviser in R. Allen Stanford’s financial company told a U.S. Senate panel on Monday that the Securities and Exchange Commission was warned about the firm’s hawking of shady investments five years before it closed the firm and accused the Texas billionaire of running a Ponzi scheme.

Leyla Wydler, hired by Stanford in 2000, said she was fired two years later — after resisting managers’ pressure to sell certificates of deposit offered by Stanford’s bank in Antigua, Stanford International Bank. She said she called the SEC and reported her suspicions about the CDs in 2004, after losing an arbitration case against the company.