(Bloomberg) -- Citigroup Inc., DBS Group Holdings Ltd. and other banks caught up in Singapore’s biggest money-laundering scandal are ramping up scrutiny of their wealthy customers and potential clients to avoid exposure to illicit flows, according to people familiar with the matter.Most Read from BloombergRussia Is Sending Young Africans to Die in Its War Against UkraineMacron and Scholz Get Trounced by Far Right in EU ElectionsPutin Is Running Out of Time to Achieve Breakthrough in UkraineSchol