Prosecutors said that they now believe that brothers of the former mayor’s wife, Maria de los Angeles Pineda, were senior members in a drug gang that is suspected of killing the students.
On Monday a judge issued a warrant for her detention ahead of a trial and linked her role to “operations with funds of illicit origin”, according investigative officer Tomas Zeron.
Prosecutors have said that the students were initially taken by police in order to prevent them from disrupting an event the mayor’s wife was speaking at, before they were passed on to a drug-trafficking gang called Guerreros Unidos.
In a Facebook post on the same day the students went missing, the mayor’s wife invited people to come to the speech, an annual conference for an organisation of which she is president, at which she promoted her campaign to become mayor in elections to be held later this year.
The mayor, Pineda, and a police chief went on the run after a mass grave was found in the town of Cocula, 10 miles from where 43 students were last seen before they disappeared.
Now, the mayor has also been charged with murder, kidnapping, and organised crime, but these are charges that relate to events unrelated to the missing students.
Prosecutors allege that the mayor’s police force worked hand in hand with the “narco” gang alleged to be linked to his wife
The students, teachers training in the Ayotzinapa College, went missing on 26 September after their buses were stopped and attacked by police.
Their subsequent disappearance shocked Mexico, leading to national protest and a crisis for the government.
The drug gang took the students to a municipal dump where they were executed and their bodies then burned for 15 hours with wood, gasoline and plastic. The remains were put in plastic bags and thrown in a nearby river.