The abduction of the youths by corrupt police working with a violent drug gang drew international outrage and led to widespread condemnation of the administration of Mexico’s former president, Enrique Pena Nieto.

A spokeswoman for the attorney general’s office confirmed that new investigations were  underway in Guerrero.

Pena Nieto’s successor, Andres Manuel Lopez Obrador, took office in December pledging to re-open the case. His government has called the original probe into the crime “discredited” and vowed to go after the officials who led it.

Angela Buitrago, a consultant named by the Inter-American Commission on Human Rights who is helping to oversee the new probe, said it was also important to investigate military officials who were present in Iguala five years ago.

According to the Pena Nieto administration’s account, local drug gang Guerreros Unidos mistook the students for members of a rival outfit, killed them, incinerated their bodies in a nearby garbage dump and tipped their remains into a river.

However, the remains of only one of the 43 were ever definitively identified, and a group of independent experts later picked several holes in the official version of events.

The U.N. human rights office said in a report last year that it appeared Mexican authorities had tortured dozens of people during the investigation. Out of 142 suspects detained in the case, more than half have been released.