The October 2008 edition (.pdf) of The SAR Activity Review, Trends, Tips and Issues published by the Financial Crimes Enforcement Network, has a great story on page 29 about a marijuana smuggling and money laundering operation.
The organization was concerned that the cash smelled like marijuana. The benk tellers even noticed the smell of marijuana on the money. The organization ended up washing and ironing the cash to remove the smell.
Too late. The teller filed a Suspicious Activity Report on the marijuana money which then focused law enforcement on subsequent deposits. Law enforcement had previously been keeping an eye on individuals in the organization. Over the course of the investigation, they tracked more than 1,000 kilograms of marijuana that the organization distributed into the local market.
Dirty money lead to 30 jail sentence for the leader of the organization.