The glimpse into the accounting practices of Lehman Brothers in the period when it was heading for bankruptcy is revealing an extraordinary story.

The collapse of the investment bank has come to be seen as the start of the world financial crisis, and it is now clear that up to $50bn in loans and investment was effectively concealed from the public gaze as it tried to shore itself up.

And the controversial accounting methods were approved by London solicitors, and not picked up by the external auditors, Ernst and Young.

John Moulton from venture capitalist Better Capital, and Shadow Chancellor George Osborne, discusses how Lehman Brothers were able to hide $50bn of debts from regulators despite checks by auditors.