Omar Trevino Morales, alias Z-42, was arrested in a pre-dawn raid in a suburb of the northern city of Monterrey, federal officials said.
The Mexican government had offered a €1.8m reward for his capture on weapons and organised crime charges. The suspect is the brother of Miguel Angel Trevino Morales, described as the most bloodthirsty leader of Mexico’s most violent cartel.
The US Drug Enforcement Administration had offered a €4.5m reward for his capture, saying he was wanted on drug-trafficking charges, but listed ‘Omar’ as an alias and his given name as Alejandro.
Miguel Angel was arrested in July 2013, almost a year after marines killed the other biggest leader in the Zetas, Heriberto Lazcano ‘El Lazca’.
The Zetas carved a path of brutality, bloodshed and mutilated bodies across northern Mexico during their turf battles with the rival Gulf cartel.
Much of the violence along Mexico’s north-east border, however, is now due to internal battles among factions of the Gulf cartel.
The capture of Omar Trevino Morales comes just a few days after Friday’s arrest of another big cartel leader, Servando Gomez, alias ‘La Tuta’.
Gomez allegedly led the Knights Templar, a pseudo-religious drug gang that built up control of many sectors of the economy in the western state of Michoacan.