Mexican cartels are working from within Colombia to traffic cocaine and taking a more active role in production of illegal drugs, Colombia's anti-narcotics director said on Monday.
"We have discovered that there are Mexican cartels which have arrived in Colombia basically to negotiate and transport the drug themselves," General Ricardo Restrepo of the national police told reporters.
"This gives them better returns and means Colombian traffickers are at less risk of being captured or caught in foreign judicial investigations," he said.
Colombian authorities have said for years that Mexican cartels have ties to local cocaine producers, but this is the first time they have mentioned the presence of active foreign traffickers in the country.
He did not name the cartels involved in sending operatives, but Colombian authorities have previously reported arrests of alleged members of the Sinaloa and the Zetas cartels, as well as seizures of drugs shipments presumably destined for those groups.
Colombia is one of the world's largest producers of cocaine, with an estimated output of 290 tons per year, according to the United Nations Office on Drugs and Crime.
The nation's once-prolific drug cartels now act primarily as producers, after being weakened by a U.S.-backed military offensive and losing control of trafficking routes to Mexican groups, which now take the lead in smuggling narcotics like cocaine, heroin and marijuana to the United States and Europe.
Leftist rebel groups, as well as crime gangs made up of right-wing ex-paramilitaries, are said to be deeply involved in narcotics production.