Enforced by HM Revenue and Customs.

http://www.hmrc.gov.uk/mlr/your-role/nominated-officer.htm

Businesses that are regulated by the Money Laundering Regulations must appoint a 'nominated officer' or Money Laundering Reporting Officer who must be an employee of the business.

Money Laundering Regulations are designed to protect the UK financial system. If your business is covered by the regulations you must put in place certain controls to prevent it being used for money laundering by criminals and terrorists. These include appointing a 'nominated officer', checking the identity of customers and keeping all relevant documents. You must also report any suspicious activity to the Serious Organized Crime Agency.

Introduction to the Money Laundering Regulations

UK financial and credit businesses, accountants and real estate agents.

http://en.wikipedia.org/wiki/Money_laundering