A crisis gripping Goldman Sachs deepened today as Britain and Germany moved towards joining the US in pursuing a fraud investigation against the Wall Street bank for allegedly fiddling clients out of $1bn ($650m) through a misleading mortgage investment deal. Gordon Brown ordered a special investigation into Goldman, accusing the bank of "moral bankruptcy". He threatened to block multimillion-pound bonus payouts if the firm is found guilty of wrongdoing. In Berlin, Angela Merkel's government said it had sought information from the US Securities and Exchange Commission with a view to evaluating "legal steps" against Goldman. Goldman's shares dived by 13% on Friday when the SEC charged the firm with collaborating with a hedge fund, Paulson & Co, to sell a deliberately skewed package of doomed mortgages in 2007, leaving clients including Royal Bank of Scotland and a German bank, IKB, nursing losses of more than $1bn.