The drug-running Medellin cartel of Colombia has bought the services of that country's most infamous guerrilla group to do the cartel's dirty work. The revolutionary group, called the "April 19 Movement," or M-19, has acted as hired gun for the multibillion-dollar cartel, according to highly classified U.S. intelligence reports.

The most notorious liaison between the drug runners and the terrorists happened in 1985 when M-19 stormed a Colombian courthouse. One hundred people were killed in the resulting shootout with police, including 12 Colombian supreme court justices. M-19 wanted the world to believe the siege was an ideological statement. Intelligence sources now tell us that the drug cartel paid M-19 $5 million to take over the courthouse.

The takeover fit into an increasingly violent program by the cartel to bully the impotent Colombian government and stymie the U.S. war on drugs.

M-19 and the Medellin cartel have not always been so tight. M-19 was formed in 1970 and was named after the date that year when a populist ex-president favored by the rebels lost an allegedly fraudulent election. At its greatest strength, M-19 numbered approximately 8,000 guerrillas, but today it may have fewer than 1,000.

In 1979, M-19 tunneled into an army arsenal in Bogota and made off with 5,000 guns. In 1980, M-19 stormed the embassy of the Dominican Republic in Bogota and took 52 hostages, including 15 ambassadors. The American ambassador, Diego Asencio, was one of those held for 61 days, after which the hostages were freed as the guerrillas escaped to Cuba. M-19 took over the embassy to call attention to human rights violations in Colombia and to guarantee fair treatment of guerrillas who were in jail in that country.

M-19's normal method of operation was to pay its way by kidnapping wealthy families and collecting ransoms.

In late 1981, however, M-19 kidnapped the wrong person -- the daughter of Colombia's alleged first family of cocaine, the Fabio Ochoa family of Medellin. The Ochoas reasoned that neither they, nor anyone who was prospering in the drug trade, would be safe from kidnappings.

The Ochoas banded with 200 other narcotics traffickers to form the Medellin cartel. Its original purpose was to wage war against M-19.

M-19 released the Ochoa's daughter after the cartel murdered dozens of guerrillas. It was the beginning of a strange friendship. M-19 began a hands-off policy toward the cartel, and the cartel put M-19 on the payroll.

On Nov. 6, 1985, M-19 took over the five-story marble Colombian Palace of Justice in downtown Bogota. It is one block from the Colombian congress and two blocks from the presidential mansion. Colombian soldiers besieged the building for 27 hours, then stormed it with grenades and gunfire. All 35 rebels died, along with 12 of the 24 supreme court justices.

We have learned from the Central Intelligence Agency and other intelligence sources that the crime was motivated more by greedy drug lords than ideological fanatics. The Medellin cartel wanted to harass the supreme court and destroy government files on cartel members who faced extradition to the United States on drug charges. A siege by a terrorist group would provide just the right cover.

The sum paid to M-19 for its services, $5 million, was pocket change for the cartel, which makes as much as $7 billion a year supplying the United States and Europe with cocaine. About 80 percent of the cocaine smuggled into the United States comes from the Medellin cartel.

M-19 has been paid by the cartel for other assassinations of government officials, judges, policy officers and journalists. Some "sicarios," as the hit men are known, will kill for as little as $50.

The cartel may be cozying up to one leftist group, but evidence indicates it also has been killing other leftists by the hundreds -- particularly supporters of Colombian Revolutionary Armed Forces (FARC).

FARC was the oldest and largest leftist guerrilla group in Colombia until it struck a deal with the government in 1984 and became a legitimate political party, the Patriotic Union. Since then, it has become the most successful leftist party in Colombian history.

Our sources say the Medellin cartel leaders, who have used their drug profits to become the largest landholders in Colombia, fear that the growing power of the leftist party will lead to land reform. They don't want to see their valuable land holdings divided up among the peasants.