The Monetary Authority of Singapore is investigating severalbanks for potential violation of anti-money laundering rules in theirtransactions linked to Malaysian state investment fund 1Malaysia DevelopmentBhd., or 1MDB, Reuters reported July 17, citing "three people withknowledge of the matter."

The Singapore central bank is looking at the banks'operations to find out if they exercised due diligence in theirknow-your-customer rules or if they were careful in screening politically exposedpersons, sources said.

The banks under review include , , andCoutts International.

The probe could lead to fines and other penalties for thebanks involved, said the sources. The banks have been in contact with theSingapore regulator and MAS will make an announcement if it will take anypunitive action against the banks being investigated, the sources added.

The 1MDB issue surfaced in 2015 after Malaysian governmentinvestigators traced hundreds of millions of dollars of funds that had flowninto the private accounts of the country's prime minister, Najib Razak, througha range of intermediaries. The discovery led to cross-border probes in severaljurisdictions, including Malaysia, Switzerland and the U.S.

UBS recently reported suspicious transactions related to IMDB to MAS,which started an investigation by the regulator.