BCCI’s demise began, in 1986, when a US Customs undercover operation led by Special Agent Robert Mazur infiltrated the bank’s private client division and uncovered their active role soliciting deposits from drug traffickers and money launderers. This two year undercover operation concluded in 1988 with a fake wedding that was attended by BCCI officers and drug dealers from around the world who had established a personal friendship and working relationship with undercover agent Mazur. At the same time he was dealing undercover with BCCI executives, Mazur used his undercover operation to establish a relationship with the hierarchy of the Medellin Cartel as one of their sources for laundering drug proceeds.US Customs agents gots some chops!
We'll also note here that the Wikipedia article fails to make any mention of this:
... evidence of [BCCI] ties to the highest levels of the US government under Ronald Reagan and George H.W. Bush, extensively uncovered by investigators, was repeatedly rebuffed by superiors and by regulators. It is worth noting that the Treasury Department official responsible for scrutinizing BCCI’s affairs in the Reagan-Bush administration was assistant secretary for enforcement John M. Walker Jr.—who happened to be the cousin of George H.W. Bush.Honestly, how many cover-ups does one family get?