Royal Bank of Scotland will be required to pay $10 billion to settle lawsuits in the US over its role in selling the complex investments that helped cause the credit crunch. US regulators are thought to be targeting a number of banks, including state-backed RBS and Barclays, for selling toxic bonds or investments backed by US mortgages, including sub-prime loans, to investors. According to analysis prepared for the board of one large Wall Street bank, RBS could have to pay between $4 billion (£2.4 billion) and $10 billion (£6.1 billion), based on previous settlements. In November JPMorgan paid $13 billion to settle all mortgage bonds litigation with the US government. The analysis claims that the banks collectively may have to pay $50 billion to US authorities to settle claims arising from the sale of the disastrous investments.