Cyber crime and political upheaval are the two biggest financial crime risks facing banks over the next year, a report said.
A survey of 200 professionals across banking and asset management found 44% felt new criminal techniques, like cyber crime, posed the largest threat to firms.
However, the report by LexisNexis Risk Solutions said 37% believed geo-political change, such as tighter sanctions imposed by the United States, presented an even greater financial crime risk.
Dean Curtis, UK managing director at LexisNexis Risk Solutions, said: "Imposing sanctions has recently been the US tool of choice when responding to an international threat.
"Over half of these sanctions have been implemented since 2009 and the Trump administration may potentially continue to utilise sanctions in favour of costly military action.
"Financial institutions have found managing evolving sanctions policies and the introduction of new targeted sanctions tools, such as the sectoral sanction regime, to be a significant challenge, making them understandably concerned about the need to manage and update risk policies, process and controls."
Changes to sanctions following the election of US President Donald Trump were of more concern to financial crime professionals than Britain's vote to leave the European Union, the report said.
It added that 30% felt Brexit would help fight criminals, while 14% believed it would have a negative impact and 56% were unsure.
Meanwhile, 92% were concerned old technology at organisations could make it harder to fight financial crime over the next two years.
The threat facing the financial firms was underscored by WannaCry ransomeware cyber attack earlier this month, which hit more than 300,000 computers in 150 countries, crippling organisations and global companies.