At Prime Minister's Questions, Mr Cameron said the manipulation of the key Libor inter-bank borrowing rate by Barclays traders was "outrageous" and those responsible for "spivvy and probably illegal activity" should be held to account.
Oil producers would seem to be the ones most likely to sell oil and drive prices down, but some of them also have access to physical supplies, key to any real manipulation.
Mr Browne said the BBA, which was in charge of collating the data used to set Libor - a key bank lending rate which became discredited after revelations of manipulation by banks - would do everything it could to fix the issue.
Berkshire Bank has sued a group of large banks that sets a key global interest rate, saying it was cheated out of interest income through alleged rate manipulation.