In 1987, the Senate Subcommittee on Narcotics, Terrorism and International Operations, led by Senator John Kerry, launched an investigation of allegations arising from reports, more than a decade ago, of contra-drug links. One of the incidents examined by the "Kerry Committee" was an effort to divert drug money from a counternarcotics operation to the contra war.
On July 28, 1988, two DEA agents testified before the House Subcommittee on Crime regarding a sting operation conducted against the Medellin Cartel. The two agents said that in 1985 Oliver North had wanted to take $1.5 million in Cartel bribe money that was carried by a DEA informant and give it to the contras. DEA officials rejected the idea.
The Kerry Committee report concluded that "senior U.S. policy makers were not immune to the idea that drug money was a perfect solution to the Contras' funding problems."
But in contrast to the emphasis of Kerry's summary of this, note the money in question had been previously confiscated during a bust of Sandinista-linked elements of the Medellin Cartel; it was not raised from drug-running by the NSC or CIA. Also note that North's idea on this was rejected--my guess is because the confiscated money was still considered evidence as long as the prosecution in question was ongoing.