The Serious Fraud Office has launched a probe into payments made between Barclays and Qatar during the financial crisis.

The bank said last month the matter was being investigated by the Financial Services Authority but yesterday revealed the fresh inquiry. Barclays is thought to be looking to see if disclosure of payments to advisers was sufficient when it raised more than £5 billion from Middle Eastern investors in 2008.

Meanwhile, US-based bank Citigroup, which has 11,000 UK staff, agreed to pay $590 million (£373m) to settle a lawsuit by investors alleging the bank hid risks tied to toxic assets. The bank was accused of repackaging collateralised debt obligations and reselling them to itself to hide exposure to the securities.