The Government Accountability Office (GAO) investigations into CIA-linked illegal activities are often stymied - a process well documented in files discussing the GAO’s attempt to investigate General Noriega’s ties to drug trafficking, and what the Intelligence Community knew, and when. Documents previously leaked to the Washington Post have now been declassified, confirming the Post’s reporting and providing new details about how CIA blocked all of GAO’s audits touching on any subject which required oversight.
https://www.muckrock.com/news/archives/2017/may/31/noriega-CIA-GAO/