Fast-forward to November 2009 and the UK regulator, the Financial Services Authority (FSA) fined UBS £8m for "systems and controls failures that enabled employees to carry out unauthorised transactions involving customer money on at least 39 accounts, which took place between January 2006 and December 2007."

At the time, the £8m fine was the third largest fine the FSA had ever imposed. The FSA said in a statement that UBS agreed to settle at an early stage of the FSA's investigation meaning it qualified for a 20 percent discount. Without the discount, the FSA would have imposed a financial penalty of £10m.

"These employees were able to take advantage of UBS' inadequate systems and controls, giving them free rein to make unauthorised trades with customer money that they were then able to conceal," said Margaret Cole, FSA director of enforcement and financial crime.