Mexican police have captured an alleged former Sinaloa drug cartel lieutenant accused of being involved in the killings of more than 350 people found in mass graves in 2011, Belfast Telegraph said.

Police in the northern state of Chihuahua detained Mario Nunez, 39, also known as "M-10", on Wednesday, August 28 in the border city of Ciudad Juarez, federal security spokesman Eduardo Sanchez said.

Nunez, a former police officer, began working with the Juarez Cartel before joining the rival Sinaloa organisation allegedly led by Mexico's most-wanted man, Joaquin Guzman.

The government partially blames Nunez for an upsurge in drug violence that brought shoot-outs in broad daylight, ambushes of police and kidnappings to Ciudad Juarez, which is across from El Paso, Texas.