NEW YORK (AP) -- Bernard Madoff's auditor has pleaded not guilty to securities fraud.
Prosecutors say accountant David Friehling rubber-stamped Madoff's books for 17 years without confirming their accuracy.
He is the only person besides Madoff facing criminal charges in the case in which thousands of people lost billions of dollars.
Madoff is serving a 150-year sentence at a prison in North Carolina.
Friehling waived his right to have a grand jury consider his case Friday before entering his not guilty plea at a federal court in Manhattan.
Friehling was Madoff's auditor from 1991 to 2008. Authorities say if Friehling had done his job, Madoff's financial statements would have shown his company owed billions of dollars to customers.