NEW YORK (Bloomberg) - Bernard Madoff's brother, sons and niece asked a bankruptcy judge to throw out a suit filed against them by the trustee liquidating Madoff's firm, who claims they contributed to investor losses at the firm.

Bernard Madoff's brother, Peter Madoff, sons Andrew and Mark Madoff and niece Shana Madoff Swanson filed papers in US Bankruptcy Court in New York on Monday asking Bankruptcy Judge Burton Lifland to dismiss the suit, which seeks to recover money for cheated Madoff investors. All four family members held positions at the defunct firm.

In their legal brief, Madoff sons Mark and Andrew Madoff claim they immediately reported the fraud to authorities when they learned of it and that they are "among the numerous victims of their father's terrible crimes".

Bernard Madoff is serving a 150-year prison sentence after pleading guilty to running a $65 billion Ponzi scheme, the biggest in history.