The City regulator has fined Royal Bank of Scotland (RBS) £5.6m after deciding inadequate systems and controls could have given terrorists access to funds.A Financial Services Authority (FSA) investigation into the bank's compliance with UK anti-money laundering regulations found deficiencies in its set-up between December 2007 and December 2008, mainly to do with UK financial sanctions screening.British companies are not allowed to provide financial services to anyone on the Treasury's sanctions list, so their policies and procedures must make sure this doesn't happen.But RBS and its NatWest, Ulster Bank and Coutts businesses failed to adequately screen both their customers, and the payments they made and received, against the list. "This resulted in an unacceptable risk that RBS could have facilitated transactions involving sanctions targets, including terrorist financing," the FSA said.Today's fine is the biggest ever imposed by the regulator for breaking rules on financial crime.