They found the bodies in a boarded-up house on city outskirts, in a neighbourhood buttressed by mountains whose residents are too poor or too frightened to make much fuss.

The four corpses were the latest in a series of gruesome discoveries inside empty houses in Tlajomulco, a suburb on the southern outskirts of Guadalajara, Mexico’s second city. Even after the authorities removed them, the stench remained.

“My wife, she smelled something,” said Francisco Palacios de la Paz, 42, one of the few people willing to speak in the neighbourhood. “I saw the police in there, but I didn’t know what it was until I read about it in the newspaper.”