British bank Barclays has been fined £290 million for trying to manipulate a key bank interest rate which influences the cost of loans and mortgages.
The BBC reports that the bank's traders lied to make the bank look more secure during the financial crisis and sometimes, working with traders at other banks, to make a profit.
Barclays said the actions fell well short of standards. Chief executive Bob Diamond and three other executives are to give up their annual bonus this year.
The Financial Services Authority is now looking into other banks.
The penalties from the British financial watchdog and US authorities followed "serious and widespread" misconduct, the authority said.
The fine is part of an international investigation into the setting of interbank rates between 2005 and 2009.
It seems highly likely that other banks, and in other countries, will face similar sanctions to that of Barclays, the BBC says.
Barclays' misconduct relates to the daily setting of the London Interbank Offered Rate (Libor) and the Euro Interbank Offered Rate (Euribor).
These interest rates directly influence the value of trillions of dollars of financial deals between banks and other institutions. They can also affect lending rates to the public, for instance, with some mortgage deals.
It is not yet clear whether Barclays staff had succeeded in manipulating the interest rates to its advantage and therefore whether it had any impact on borrowers.