Ben Bernanke said the Fed and the US financial watchdog were "looking into a number of questions" related to banks' derivatives arrangements with Greece.

But he stopped short of saying an official inquiry was under way by either the Fed or the regulator.

Goldman Sachs was the only firm which Mr Bernanke mentioned by name.

Earlier this week a Goldman Sachs boss defended the bank's 2001 debt-swap deal with Greece that may have allowed the country to mask the extent of its debt woes.

Yes, this too shall pass without punishment.