Andrew and Mark Madoff, along with Bernard Madoff's niece Shana, are being sued for $198 million by court-appointed trustee Irving Picard in allegations that state they were "completely derelict" in their duties at Madoff Investment Securities.
But their lawyer Martin Flumenbaum said that the brothers were involved in only the legitimate aspects of the Madoff financial empire, such as the market-making and trading businesses "they had spent their professional lives building".
"For this, among many other reasons, they rank among the numerous victims of their father's terrible crimes," said Mr Flumenbaum.
Earlier this month, victims of Bernard Madoff who had invested in the LuxAlpha fund were told they could not sue UBS, the bank which assisted in the establishment of the investment vehicle.
It was ruled that they should instead seek compensation via the liquidators of LuxAlpha.
By Asim Shah