Mexico on Friday arrested a former top prosecutor who led the heavily criticised investigation into the disappearance of 43 students in 2014, on charges of forced disappearance, torture and obstruction of justice.

Jesus Murillo Karam is the highest profile arrest so far in connection with the case, which shocked the nation and the world.

The former attorney general is considered the architect of the so-called “historical truth” version of events presented in 2015 by the government of then-president Enrique Pena Nieto, which was widely rejected, including by relatives. Current President Andres Manuel Lopez Obrador reopened the investigation shortly after his election in 2018.

Murillo, a former heavyweight of the once-dominant Institutional Revolutionary Party (PRI) who lives in the Mexico City area, was arrested outside his home, according to a statement from the attorney general’s office. Murillo held the post of attorney general from 2012 – 2015.

The 43 students from the Ayotzinapa Rural Teachers’ College in the southwest state of Guerrero went missing as they were travelling by bus to a demonstration.

Investigators say they were detained by corrupt police and handed over to a drug cartel which mistook them for members of a rival gang, but exactly what happened to them has been hotly disputed.

According to the official 2015 report, cartel members killed the students and incinerated their remains at a rubbish dump, but those conclusions were rejected by the families as well as independent experts and the office of the United Nations High Commissioner for Human Rights.

Soldiers check people’s identity during a military search operation for the 43 missing students after fighting in the area in September 2014. A report released this week said the military bore some responsibility for what happened

International experts criticised the official inquiry as riddled with errors and abuses.

Murillo’s arrest comes a day after Mexico’s top human rights official, Alejandro Encinas, called the students’ disappearance a “state crime” and that the military bore at least partial responsibility, either directly or through negligence.

“Their actions, omissions or participation allowed the disappearance and execution of the students, as well as the murder of six other people,” said Encinas, who is also deputy interior minister.

Encinas also said the highest levels of Pena Nieto’s administration orchestrated a cover-up in the aftermath of the incident.

Lopez Obrador said on Friday that any soldiers and officials involved in the disappearance must face justice.

“Publicising this atrocious, inhuman situation, and at the same time punishing those responsible, helps to prevent these deplorable events ever happening again” and “strengthens institutions,” the president said.

“We said from the beginning that we were going to speak the truth, no matter how painful it was,” he told reporters during a visit to the northwestern border city of Tijuana.