HOUSTON -- The last two defendants convicted for helping disgraced financier R. Allen Stanford bilk investors out of more than $7 billion in one of the biggest Ponzi schemes in U.S. history were each sentenced to 20-year prison terms by a federal judge Thursday.Lawyers for Gilbert Lopez Jr., the ex-chief accounting officer for one of Stanford's companies, and Mark Kuhrt, the ex-global controller for another company, had asked for lesser prison terms, saying their clients were not as culpable as two other former executives who received significantly smaller sentences.Jack Zimmermann, Lopez's attorney, told U.S. District Judge David Hittner that his client was "down the chain" of Stanford's business empire and "had no decision-making authority in any of the things that ran this fraud."Richard Kuniansky, Kuhrt's attorney, said his client believed that Stanford legitimately borrowed investor funds and was going to pay the money back.Lopez and Kuhrt were both convicted at trial last year of conspiracy to commit wire fraud and of nine counts of wire fraud. Hittner sentenced each defendant to 20 years for each count, to be served at the same time. He also fined Lopez $25,000 but waived a fine for Kuhrt.Lopez, 70, covered his face with his hands after being sentenced, while Kuhrt, 40, stared down at the floor with his eyes closed. Relatives in the courtroom cried after the sentences were announced. Lopez's attorney had asked for a three-year prison term, asking for leniency in part based on his client's age. Kuhrt's attorney had asked for five years.Prosecutors said Stanford, a onetime billionaire, persuaded investors to buy certificates of deposit from his bank on the Caribbean island nation of Antigua, then used that money to bankroll a string of failed businesses and his lavish lifestyle, which included yachts, a fleet of private jets and sponsorship of cricket tournaments. Authorities said Stanford and others in his companies lied to investors from more than 100 countries, telling them their funds were being safely invested in stocks, bonds and other securities.Prosecutor Jeffrey Goldberg told Hittner that both Lopez and Kuhrt helped hide the massive fraud by misrepresenting to investors in reports and other documents that their money was safe and Stanford's bank was on solid financial ground.