A leading City bank is to pay a record £1.6 billion fine as part of a settlement with US and UK regulators over the rigging of interest rates.
Deutsche Bank's fine from the UK's Financial Conduct Authority (FCA) amounted to a record £227 million after the watchdog found traders manipulated rate submissions between January 2005 and December 2010. The FCA also accused the lender of repeatedly misleading it.
Other fines from authorities in the United States included 800 million US dollars (£532 million) from the Commodities Futures Trading Commission.
Georgina Philippou, the FCA's acting director of enforcement and market oversight, said: "This case stands out for the seriousness and duration of the breaches by Deutsche Bank - something reflected in the size of today's fine.
"One division at Deutsche Bank had a culture of generating profits without proper regard to the integrity of the market. This wasn't limited to a few individuals but, on certain desks, it appeared deeply ingrained."
The manipulation involved at least 29 Deutsche Bank staff and was primarily based in London but also Frankfurt, Tokyo and New York.
The FCA said their behaviour went unchecked because of inadequate systems and controls, with the Bank taking more than two years to identify and produce all the relevant audio recordings it had requested.
Deutsche Bank tried to claim to the FCA that its systems had been adequate, even though the person making this statement knew it to be false.
Ms Philippou added: "Deutsche Bank's failings were compounded by them repeatedly misleading us. The bank took far too long to produce vital documents and it moved far too slowly to fix relevant systems and controls.
"This case shows how seriously we view a failure to cooperate with our investigations and our determination to take action against firms where we see wrongdoing."
Other fines by the City watchdog in relation to the fixing of Libor and Euribor rates saw Barclays and UBS pay £59.5 million and £160 million respectively. Royal Bank of Scotland was hit with a fine of £87.5 million in relation to Libor misconduct.
The FCA said the involvement of managers and senior managers in the misconduct "aggravates the seriousness of the breaches".
Most of it took place in London while it also extended to trading desks in Frankfurt, Tokyo and New York.
The probe found that on some occasions staff submitting Libor rates would solicit requests on the numbers to put in from derivatives traders who stood to profit.
On one occasion, a manager in September 2005 wrote to a derivatives trader "libors any requests" to which the trader replied: "HIGH FREES [THREES], LOW 1MUNF [MONTH]".
Another trader in April 2005 requested "COULD WE PLS HAVE A LOW 6MTH FIX TODAY OLD BEAN?".
On another occasion in December , a manager said: "COULD I BEG YOU FOR A LOW 3M [EURIBOR] FIXING TODAY.. THAT WOULD BE THE BEST XMAS PRESENT ;)".
In August 2010, a submitter asked to put in a lower Libor rate was told by a colleague: "We're going to get in trouble if we keep moving it up and down".
In January 2011, a compliance officer at Deutsche signed a confirmation to the British Bankers' Association (BBA) that the bank's Libor submissions had been audited, but this was false, the FCA found.
In a later email, the same member of staff described the BBA confirmation as an "an a**e-covering exercise".
Deutsche Bank was found by the FCA to have failed to pass on to it a report from the German regulator on the rate-rigging and claimed that it was banned from doing so even though "there was no such prohibition".
In addition, it formally attested to the FCA that its systems and controls related to Libor submissions were adequate, even though the person drafting this assertion knew it to be false.
Deutsche Bank's response to some of the regulator's enquiries had been "slow and ineffective" and prolonged the length of the probe.
It found inadequacies in Deutsche's audio system for recording traders' telephone calls meant the bank took more than two years to identify and produce all those first requested by the FCA in December 2012.
The FCA said the bank "has stated publicly that it promotes a culture of integrity" but that due to the failings it would continue to monitor efforts to change its culture.
Jurgen Fitschen and Anshu Jain, co-chief executive officers of Deutsche Bank, said: "We deeply regret this matter but are pleased to have resolved it. The bank accepts the findings of the regulators.
"We have disciplined or dismissed individuals involved in the trader misconduct; have substantially strengthened our control teams, procedures and record-keeping; and are conducting a thorough review of the Bank's actions in addressing this matter.
"This agreement marks another step in addressing the past and ensuring that the Bank earns back the trust of its clients, shareholders and society at large."
Deutsche said no current or former member of its management board was found to have been involved in or aware of the traders' misconduct.
It said it had worked "intensively" investigating the matter, with an internal inquiry involving the collection of more than 150 million electronic documents and 850,000 audio files.
The Bank said it recognised there were "defects and delays in collecting and producing documents and audio".
Today's fines come months after a blunt video message from Deutsche's markets division chief Colin Fan, warning employees that their emails, conversations and conduct would all be subject to scrutiny.
In the message last May, Mr Fan said: "You may not realise it but right now, because of regulatory scrutiny all your communications may be reviewed.
"Communications that run even a small risk of being seen as unprofessional stops right now. I need you to exercise good sense and sound judgment.
"Think carefully about what you say and how you say it. If not, it will have serious consequences for you personally."