Jorge Dan Lopez / Reuters A police officer watches one of the alleged leaders of the Sinaloa Cartel in Guatemala, Wilmar Anavisca (C), also known as "El Chino", after his arrest in the Supreme Court of Justice in Guatemala City, October 18, 2013.

The U.S. government allowed the Mexican Sinaloa drug cartel to carry out its business unimpeded between 2000 and 2012 in exchange for information on rival cartels, an investigation by El Universal claims.

Citing court documents, the Mexican newspaper reports that DEA officers met with top Sinaloa officials over fifty times and offered to have charges against cartel members dropped in the U.S., among other pledges.

Dr. Edgardo Buscaglia, a senior research scholar in law and economics at Columbia University, says that the tactic has been previously used in Colombia, Cambodia, Thailand and Afghanistan.

“Of course, this modus operandi involves a violation of public international law, besides adding more fuel to the violence, violations of due process and of human rights,” he told El Universal.

Myles Frechette, a former U.S. ambassador to Colombia, said while that the problem of drug trafficking in Colombia persists, the tactic of secret agreements had managed to reduce it.

The period when the relationship between the DEA and Sinaloa was supposed to have been the closest, between 2006 and 2012, saw a major surge of violence in Mexico, and was the time when the Sinaloa cartel rose significantly in prominence.

[El Universal]