Richard Fuld, the disgraced head of Lehman Brothers, said he would wonder "until they put me in the ground" why the US government did not rescue the 158-year-old Wall Street firm and claimed regulators knew the full scale of its condition far before its collapse.

Fuld said he took full responsibility for his actions ahead of the downfall of Lehman, but said US regulators were aware of everything at the firm and knew how it was pricing its distressed assets in the months prior to its bankruptcy.

Despite his acceptance of his role before the collapse, US lawmakers expressed outrage to Fuld about Lehman on Monday, saying that Fuld, board members, regulators and Congress all shared blame for its downfall.