This action is the most appropriate because it demonstrates the local manager's responsibility and accountability for the sanctions compliance program. Sanctions screening is an important part of the Know Your Customer (KYC) and Anti-Money Laundering (AML) processes, as it helps to identify and prevent transactions with sanctioned individuals or entities, which could expose the financial institution to legal, regulatory, and reputational risks. Failing to perform sanctions screening could result in violations of sanctions laws and regulations, which could lead to fines, penalties, sanctions, or even criminal prosecution. Therefore, the local manager should immediately inform senior management of the issue, so that they can take corrective actions, such as implementing screening procedures, conducting a risk assessment, reviewing existing customers, reporting any potential violations, and providing training and guidance to the staff.
The other actions are not appropriate because they either do not address the root cause of the problem, or they could worsen the situation. Starting screening new customers without informing senior management could create a false sense of compliance, and it could also miss the existing customers who may be sanctioned.
Immediately informing the regulators without informing senior management could undermine the trust and communication within the organization, and it could also trigger an investigation or enforcement action before the issue is resolved internally. Doing nothing because the department only handles a very small number of mortgages could be a sign of negligence or indifference, and it could also expose the financial institution to significant risks, as even one transaction with a sanctioned party could have serious consequences.
References:
* CAMS Certification Package - 6th Edition | ACAMS, Chapter 4: Developing and Implementing an AML Training Program, pp. 97-98
* CAMS Certifications: How to Get CAMS Certified | ACAMS, CAMS Study Guide, pp. 76-77
* What is Sanctions Screening and How Does It Work? | Jumio, Introduction and Benefits of Sanctions Screening
* Sanctions Screening: Challenges and Control Considerations, Background and Regulatory Expectations for Sanctions Screening
* Sanction Screening: A Complete Guide | KYC AML Guide, What is Sanction Screening and Why is it Important?

This is an emerging risk associated with cyber-enabled fraud because the use of false identities and documents can allow criminals to disguise their activities and evade detection. In such cases, the name and address provided on the account may not match the name and address on the government-issued documentation. This discrepancy can be difficult to detect, making it a potential risk for financial institutions.

Reference: https://www.treasury.gov/resource-center/faqs/Sanctions/Documents/faq_all.html
''Who must comply with OFAC regulations?U.S. persons must comply with OFAC regulations, including all
U.S. citizens and permanent resident aliens regardless of where they are located, all persons and entities within the United States, all U.S. incorporated entities and their foreign branches. In the cases of certain programs, foreign subsidiaries owned or controlled by U.S. companies also must comply. Certain programs also require foreign persons in possession of U.S.-origin goods. please refer to:
https://home.treasury.gov/policy-issues/financial-sanctions/frequently-asked-questions/ofac-consolidated-frequen

When a financial institution is requested to provide data and information to a law enforcement agency for matters related to the financing of terrorism, assistance cannot be refused on the grounds of tipping-off.
Tipping-off refers to disclosing to a customer or any third party that a suspicious activity report (SAR) has been filed. However, in this specific context, the obligation to provide information to law enforcement takes precedence over any concerns related to tipping-off. Financial institutions must cooperate fully with law enforcement agencies in such cases to combat money laundering and terrorist financing12.
References:
31 CFR 1010.520 (a) (2)
FinCEN: Fact Sheet on the Rapid Response Program (RRP)
FinCEN.gov
Federal Financial Institutions Examination Council (FFIEC) BSA/AML Examination Manual

During an internal investigation, employees should be instructed to do the following actions:
Inform counsel of all request for documentation: This is to ensure that the legal rights and obligations of the organization and the employees are protected and respected. Counsel can also advise on the scope, relevance, and confidentiality of the requested documents1.
Make copies of all documents provided to law enforcement: This is to maintain a record of the information that has been disclosed and to prevent any loss or alteration of the original documents. Copies should be made before the documents are handed over to law enforcement2.
Keep a log of the documents requested: This is to track the progress and status of the investigation and to avoid any duplication or omission of the requested documents. The log should include the date, time, description, and location of the documents, as well as the name and contact details of the person who requested and received them3.
Providing corporate documents directly to law enforcement, on the other hand, is not an action that employees should be instructed to do during an internal investigation. This is because law enforcement may not have the legal authority or the proper warrant to access the documents, and doing so may violate the privacy or confidentiality of the organization or the employees. Employees should consult with counsel before providing any documents to law enforcement4.
References:
1: Internal money laundering reporting | The Law Society5 2: How to Conduct Effective AML Investigations - Blog | Unit212 3: What Is The Importance Of An Internal Investigation?4 4: Anti-Money Laundering: 5 Steps to Conduct an Audit3