For weeks the news media and politicians have treated a San Jose Mercury News series linking the CIA to drug smuggling by the Nicaraguan contras in U.S. inner cities as breaking news. In fact, a battery of law enforcement agents, Congressional investigators and investigative reporters have been battling to expose elements of the operation for years -- to no avail, thanks to a massive government cover-up. Robert Knight was a founding producer, along with PNS associate editor Dennis Bernstein, of the Contragate/Undercurrents investigative news program for which Knight won the George R. Polk Award for Radio Reporting. Knight and Bernstein won The Jesse Meriton White Award for International Reporting and the National Federation of Community Broadcasting award for reporting on the Iran-Contra affair.

NEW YORK -- Veteran Drug Enforcement Agent Celerino Castillo III says he never figured his toughest anti- drug case would be against the federal government which employed him for 15 years. Last week, flanked by civil rights leaders Dick Gregory and the Rev. Joseph Lowery, he staged a public protest at DEA headquarters in Washington to demand an official investigation into the government's clandestine "contra" policy which allegedly flooded America's predominantly black communities with crack cocaine during the 1980s.

This was hardly the first effort by the veteran DEA agent to expose the story. Along with numerous other law enforcement officials, congressional investigators and investigative reporters, Castillo has been battling for over a decade to expose the government's use of drug profits to finance covert operations against Nicaragua's Sandinista government.

For Castillo, the big picture became clear around January 14, 1986 when he says he tried to alert then Vice-President George Bush at a U.S. embassy party in Guatemala. At the time Castillo was covering several Central American countries for the DEA. Convinced that "something funny" was going on at El Salvador's Ilopango military air base -- later revealed to be a prime transshipment point for contra drugs, arms and money -- he told Bush. "But he just shook my hand, smiled and walked away from me," Castillo recalls. That same day, Castillo says, Bush met with both Lt. Oliver North, then the point man at the National Security Council for sharing intelligence, transportation and military facilities with Central American drug dealers, and contra chief Adolfo Calero.

In the ensuing months, Castillo meticulously gathered his own evidence. In a Feb. 14, 1989 memo to his Guatemala-based DEA supervisor, Castillo detailed how known traffickers with multiple DEA files used hangers controlled by North and the CIA at Ilopango and obtained U.S. visas, despite their background.

"There is no doubt that they were running large quantities of cocaine into the U.S. to support the contras," Castillo told reporters in a 1994 interview on the eve of North's bid for a senate seat in Virginia. "We saw the cocaine and we saw boxes full of money. We're talking about very large quantities of cocaine and millions of dollars."

Oliver North's own notebooks are chock full of references to drug related contra operations that clearly support Castillo's claims. On July 9, 1984, when the contras were desperate for money, North wrote that he went and talked to (contra leader Federico) Vaughn, (who) wanted aircraft to go to Bolivia to pick up paste, wanted aircraft to pick up 1,.500 kilos.

Other evidence besides Castillo's reports has surfaced over the last decade that was routinely ignored or dismissed by responsible government agencies:

*An internal document of the House Committee on Narcotics Abuse and Control, dated June 25, 1986, and publicized in U.S. newspapers in March 1987, concluded that "a number of individuals who supported the contras (in both the U.S. and Central America) have suggested that cocaine is being smuggled in the U.S. through the same infrastructure which is procuring, storing and transporting weapons explosives, ammunition and military equipment for the contras from the United States."

*A City of Miami Police Intelligence Report dated September 26, 1984, states that money to support contras being illegally trained in Florida "comes from narcotics transactions." Every page of that document is stamped: "Record furnished to George Kosinsky, FBI." Justice Department head Janet Reno, then Florida's chief prosecutor, apparently saw no reason to investigate further.

*In the spring of 1986, John Mattes, a former Miami-based Federal Public Defender, began working with Senator John Kerry's office to investigate the contra drug connection. Mattes, like Castillo, had sought without success to expose link between Florida contra training camps and drug traffickers.

"What we investigated and uncovered," Mattes recalls, "was the very infrastructure of the network that had the veil of national security protecting it, so that people could load cannons in broad daylight, in public airports, on flights going to Ilopango Airport, where in fact the very same people were bringing narcotics back into the U.S., unimpeded."

When Mattes informed the FBI about the network, he said federal officials "decided that in fact they didn't want to look at the contras. They wanted to look at us and try to deter us from our investigation. We were threatened on countless occasions by FBI agents who told us that we'd gone too far in our investigation of the contras."

*In 1987 and 1988, Kerry's sub-committee on Narcotics and International Terrorism took reams of testimony on the CIA cocaine connection from CIA agents, contra mercenaries, drug pilots, Medellin cartel accountants, and law enforcement officials. Kerry said at the time that "our covert agencies have converted themselves to channels for drugs."

Despite the San Jose Mercury News' recent series on the CIA's contra policy, Castillo fears the official cover-up will continue. Both Attorney General Janet Reno and CIA director John Deutch have stated there is no evidence to support the allegations being made against the CIA. Ten years ago, the CIA dismissed allegations about its contra-drug connection as "fantasy, the most scurrilous kind of journalism."