The accountant who helped conceal Bernard L. Madoff’s record-breaking Ponzi scheme pleaded guilty yesterday, admitting in Manhattan federal court that he rubber-stamped financial statements used to deceive regulators and investors.

David G. Friehling, 49, entered guilty pleas before Southern District Judge Alvin K. Hellerstein to single counts of securities fraud and investment advisor fraud, four counts of making false filings with the Securities and Exchange Commission and three counts of obstructing or impeding administration of the Internal Revenue laws.