A scathing report by a US bankruptcy-court examiner investigating the collapse of Lehman Brothers blames senior executives and auditor Ernst & Young for serious lapses that led to the largest bankruptcy in US history and the worst financial crisis since the Great Depression.

In the works for more than a year, and costing more than $30m (€21.7m), the report by court-appointed examiner Anton Valukas paints the most complete picture yet of the free-wheeling culture inside the 158 year-old firm, whose chief executive Richard S. Fuld Jr. prided himself on his ability to manage market risk.