House.gov:
The following statement was presented by Rep. Waters on the House floor, May 13,1999:

Most Americans would assume that the CIA would never traffic in illegal drugs and would take all necessary actions to prosecute known drug traffickers. History, however, has proven that this is not the case.

For 13 years, the CIA and the Department of Justice followed a Memorandum of Understanding that explicitly exempted the CIA from requirements to report drug trafficking by CIA assets, agents, and contractors to federal law enforcement agencies. This allowed some of the biggest drug lords in the world to operate without fear that their activities would be reported to the Drug Enforcement Agency or other law enforcement authorities. This remarkable -- and secret -- agreement was in force from February 1982 until August of 1995."

I have been investigating the allegations of drug trafficking by the Nicaraguan Contras during the 1980s. My investigation has led me to the conclusion that U.S. intelligence agencies knew about drug trafficking by the Contras in South Central Los Angeles and throughout the United States and chose to continue to support the Contras without taking any action to stop the drug trafficking. Last year, the CIA Inspector General released a Report of Investigation on drug trafficking by the Contras, which confirms allegations of CIA knowledge of and support for drug trafficking in the United States by the Contras. The Report provides extensive details of the evidence available to the CIA regarding drug trafficking by the Contra rebels and their supporters.

Even more remarkable is the fact that there is evidence that the CIA has actually participated in drug trafficking activities. In the late 1980s, the CIA began to develop intelligence on the Colombian drug cartels. To infiltrate the cartels, the CIA arranged an undercover drug-smuggling operation with the Venezuelan National Guard.