Mexican police escort Alfredo Beltran Leyva after his arrest in 2008.

Story highlights

Alfredo Beltran Leyva, a kingpin behind the Beltran Leyva cartel, pleads guilty in Washinton

Leyva admitted to participating in an international narcotics trafficking conspiracy, prosecutors say

The Mexican cartel boss was once alligned to Sinaloa cartel leader Joaquin "El Chapo" Guzman

CNN  — 

A Mexican cartel boss once aligned to Joaquin “El Chapo” Guzman pleaded guilty Tuesday to conspiracy charges stemming from the importation of multiple tons of cocaine and methamphetamine into the United States.

Alfredo Beltran Leyva, a kingpin behind the Beltran Leyva cartel, pleaded guilty to participating in an international narcotics trafficking conspiracy before U.S. District Judge Richard Leon of the District of Columbia, according to a U.S. Justice Department statement.

Leyva, 45, who was indicted in August 2012 for conspiracy to distribute cocaine and methamphetamine for importation into the United States, was extradited from Mexico in November 2014.

“For decades, Alfredo Beltran Leyva helped to lead one of the world’s most notorious drug cartels, causing widespread violence and disrupting lives,” U.S. Attorney General Loretta Lynch said in the statement.

Under the plea, Leyva admitted that from 1990 until his arrest in 2008, his cartel helped finance and obtained multiton shipments of South American cocaine. The drugs were transported to Culiacan, Sinaloa and other points in Mexico, where billions of dollars in U.S. drug proceeds also were collected, according to the statement.

The organization was responsible for “murders, kidnappings, tortures and violent collections of drug debts” and payments to officials to ensure the safe passage of the shipments through Mexico, according to federal prosecutors.

Founded by the four Beltran Leyva brothers – Arturo, Carlos, Alfredo and Hector – the organization was once aligned with Guzman’s Sinaloa cartel but later switched allegiance to Los Zetas.

Los Zetas are made up of former elite members of the Mexican military. They initially worked as hit men for the Gulf cartel, before claiming their independence and battling the Gulf cartel for control of Tamaulipas and Nuevo Leon states.

Guzman was recaptured last month and returned to central Mexico’s Altiplano prison, where he escaped in July 2015 by slipping out through a tunnel. But security measures at the maximum-security prison have been tightened as the drug lord awaits extradition to the United States.