Mexican drug lord who founded ultra-violent Zetas is released from US prison

An undated police handout picture shows extradited Gulf cartel leader Osiel Cardenas with the word "Arrested" printed on it. REUTERS/Courtesy of the Procuraduria General de la Republica/File Photo

MEXICO CITY (Reuters) -One of the most notorious drug chiefs in Mexico's history, Osiel Cardenas, was released from a U.S. prison on Friday into the custody of immigration officials who may deport him.

Former leader of the Gulf Cartel, Cardenas presided over some of the bloodiest gang violence in Mexico's turbulent past and has been blamed for transforming drug trafficking by embracing hyper-violent tactics such as decapitations.