Bernard Madoff is serving a 150-year prison term in North Carolina for swindling a long list of investors [EPA]

The elder son of jailed financier Bernard Madoff has been found dead in New York in an apparent suicide.

Mark Madoff, 46, was found hanging in his apartment in Manhattan’s SoHo district, a law enforcement official said on Saturday. A family member notified police.

Mark and his brother, Andrew, were under investigation but hadn't faced any criminal charges in the massive Ponzi scheme that led to their father's jailing.

Bernard Madoff swindled a long list of investors out of billions of dollars and is serving a 150-year prison term in North Carolina.

The scandal put a harsh light on members of the swindler's family. The financier's brother, Peter, played a prominent role in the family's company.

Mark and Andrew Madoff both worked on a trading desk at the firm, on a side of the business that was not directly involved in the Ponzi scheme.

A year ago, the court-appointed trustee trying to unravel Madoff's financial affairs sued several members of the family, including the brothers, accusing them of failing to detect the fraud while living lavish lifestyles financed with the family's ill-gotten fortune.

The lawsuit accused Mark of using $66m he received improperly to buy luxury homes in New York City, Massachusetts and Connecticut.

In February, Mark's wife petitioned a court to change her last name, saying her family had gotten threats and was humiliated by the scandal.