Although Madoff originally said that he was the sole perpetrator of the fraud, prosecutors allege that he had quite a bit of help to falsify records and keep the scam going until four years ago.

FORBES: Inside the Mind of Madoff: When Did Scam Really Begin?

The two pled guilty to one count each of conspiracy to falsify books and records and wire fraud.

FORBES: Credit Suisse Traders Plead Guilty in CDO Scheme