Nov. 13 (Bloomberg) -- Two of Bernard Madoff’s former computer programmers were sued by U.S. regulators for allegedly helping to hide his fraud for more than 15 years and trying to cover their tracks after a “crisis of conscience” in 2006.

Jerome O’Hara, 46, and George Perez, 43, wrote programs to generate fake trade blotters, stock records and other documents to back nonexistent transactions, the Securities and Exchange Commission said today in a statement announcing its civil lawsuit.

“Without the help of O’Hara and Perez, the Madoff fraud would not have been possible,” George Canellos, head of the SEC’s New York office, said in the statement. “They used their special computer skills to create sophisticated, credible and entirely phony trading records that were critical to the success of Madoff’s scheme for so many years.”

Phone calls to Gordon Mehler, O’Hara’s lawyer, and Larry Krantz, an attorney for Perez, were not immediately returned. O’Hara is a resident of Malverne, New York; Perez lives in East Brunswick, New Jersey.

Madoff and his lieutenant Frank DiPascali, routinely asked the programmers for help creating records that blended real transactions at his brokerage with the fictitious balances in investor accounts, the SEC said. Madoff is serving a 150-year sentence in federal prison after pleading guilty in July. DiPascali, who also pleaded guilty, is awaiting sentencing.

“O’Hara and Perez had a crisis of conscience in 2006 and tried to cover their tracks,” the SEC said in the statement.

They allegedly sought to delete about 218 of 225 so-called special programs from a computer, known as “House 17,” used to process money management account data. They didn’t delete the monthly backup tapes, the SEC said.

O’Hara and Perez then cashed out hundreds of thousands of dollars from their personal accounts at Madoff’s firm, before confronting him and refusing to generate more bogus records, the SEC said.

To contact the reporters on this story: David Scheer in New York at dscheer@bloomberg.net; Joshua Gallu in Washington at jgallu@bloomberg.net.

Last Updated: November 13, 2009 10:10 EST