Citing people familiar with the matter, Bloomberg reported that Citigroup, DBS Holdings and several other banks are stepping up scrutiny of their wealthy clients and potential clients to avoid exposure to illicit financial flows after being implicated in Singapore's largest money laundering scandal. Private bankers at several institutions are also receiving additional training to help them identify the tactics used by criminals to disguise their backgrounds and sources of funding, according to people familiar with the matter who spoke on the condition of anonymity because they were discussing private matters. The voluntary moves show that lenders are struggling to close loopholes that allowed a group of criminals to launder more than S $3 billion (about $2.23 billion) in online gambling proceeds through at least 16 Singapore Financial Institution Groups. The scandal has damaged Singapore's image and exposed weaknesses in customer screening by local and foreign banks and brokerages. The Monetary Authority of Singapore recently completed on-site inspections of some of the banks involved, and people familiar with the matter said the banks with which the most transactions - including deposit accounts, loans and other financial services - were expected to face fines and other penalties after the financial regulator completed its review.