According to the Basel Committee on Banking Supervision's Customer Due Diligence for Banks1, banks should have policies and procedures to identify and manage high-risk customers, such as those who provide false or incomplete information, have complex or opaque beneficial ownership structures, or are involved in large or unusual transactions. In such cases, banks should apply enhanced due diligence measures, such as obtaining additional information or documentation, verifying the source and purpose of funds, conducting more frequent and intensive monitoring of account activity, and reporting any suspicious transactions to the relevant authorities. Therefore, the best course of action for the bank in this scenario is to implement enhanced due diligence procedures to monitor the account for suspicious activity, as option B suggests. Option A is not recommended, as it would imply that the bank accepts the customer without verifying his identity and background, which would expose the bank to money laundering and terrorist financing risks. Option C is not advisable, as it would terminate the relationship without investigating the origin and destination of the funds, which could hinder the efforts of law enforcement agencies to trace and recover illicit assets. Option D is also not appropriate, as it would involve sending a check to a customer whose address and identity are not confirmed, which could facilitate money laundering and fraud.
References:
5: Customer due diligence for banks - Bank for International Settlements, October 2001, pages 8-9,
13-14.