The Criminal Investigation Division, Internal Revenue Service maintains approximately ten Special Agents (criminal investigators) in Puerto Rico and approximately twenty in the Washington D.C. area. Their responsibility is the investigation of alleged tax fraud or other tax crimes outside the United States. These agents work with law enforcement/taxing officials of foreign countries and furnish information learned outside the United States back to the local IRS offices in the United States for what action the local offices deem appropriate.

In addition, the IRS Criminal Investigation Division maintains offices in the U.S. Embassies throughout the world. Agents are stationed in Europe, Asia, South and Central America and Australia as well as Mexico City, Mexico and Canada. Their function is to obtain intelligence and funnel that information back to the IRS in the United States. These agents have full diplomatic immunity and are trained, federal criminal investigators.