And still the revelations come. At the height of the financial crisis Deutsche Bank, once the great banker to German industry, now deeply involved in global investment banking, appears to have sailed closer to the wind of insolvency than previously thought.

According to a Financial Times investigation, three whistleblowers have separately complained to regulators including the Securities and Exchange Commission that the bank failed to recognise up to $12bn of losses on a huge position in derivatives structures known as leveraged super senior trades. The suggestion is that if Deutschehad accounted realistically for the decline in the value of this position, with a notional value of $130bn, its regulatory capital would have been so badly dented as to necessitate a government bailout.

The transactions concerned, which related to synthetic collateralised debt obligations, are fiendishly complicated for mere mortals to grasp. Yet the principles were simple enough. The bank wanted to insure against default by companies generally regarded as among the safest. It sought insurance from investors who were desperate for income in a world where yields had plunged to extraordinarily low levels. In exchange for posting very modest collateral with the bank, they were paid an income stream equivalent to an insurance premium.