The drugs, belonging to the Colombian Usuga Clan crime gang and valued at some $90 million, were discovered in a jungle region, General Rodolfo Palomino, the head of Colombia's national police, told reporters in Necocli.
"The shipment was ready to leave on a river to the Caribbean or the border with Panama, to be sent on to Mexico," he said.
Colombia, a major cocaine producer, turns out some 300 tons annually, according to the United Nations Office on Drugs and Crime. Authorities confiscated about 166 tonnes of the drug in 2014.
The northeastern area of Colombia is strategically important for crime gangs and leftist guerrillas who use it for clandestine trafficking of arms and drugs.
The Usuga Clan, which has at least 2,000 members, is the country's largest criminal group. In addition to drug trafficking, it is also involved in illegal mining. Colombian authorities have offered a $600,000 reward for information leading to the capture of its leader.
Many crime gangs are comprised of ex-members of paramilitary groups who officially demobilized nearly a decade ago.
Marxist rebels also reap hefty profits. Cocaine and other drugs are some of the principal sources of financing for groups fighting in the country's 50-year armed conflict, which has killed over 200,000 people.
Just last week, police discovered 3 tonnes of cocaine in the port terminal in Cartagena, a popular tourist hub on Colombia's Caribbean coast. The drugs were also bound for Mexico.