By Anahi Rama and Lizbeth Diaz
A panel of international experts have accused Mexico's government of failing to fully cooperate with their probe into the fate of 43 trainee teachers apparently massacred in 2014, the most notorious human rights case in Mexico in recent years.
The independent panel of experts on Sunday said the government's stonewalling stopped them from reaching the truth as they wrap up their work and prepare to leave Mexico.
The attorney general's office, they said, did not let them re-interview detainees accused of the crime or obtain other information in a timely fashion.
Prosecutors, meanwhile, did not pursue investigative angles that the experts had suggested.
"The delays in obtaining evidence that could be used to figure out possible lines of investigation translates into a decision (to allow) impunity," the report by the experts, commissioned by the Inter-American Commission on Human Rights (IACHR), said.
A spokesman for the attorney general's office said the office would probably comment after the experts concluded a news conference.
The grisly case underscored the deep impunity that reigns in many hyper-violent parts of Mexico, and tarnished President Enrique Pena Nieto's reputation.
Mexico's government says that corrupt police handed the students over to drug gang henchmen in late 2014, who then incinerated them at a garbage dump in the southwestern Mexican state of Guerrero.
The experts say that the government's fire theory is scientifically impossible given the heat needed to reduce human remains to ash.
The remains of just one of the 43 has been identified from a charred bone fragment.
IACHR has said it will not renew the experts' term because the government was opposed to an extension.
In January, the experts said, they started to encounter stiff resistance from prosecutors.
Dozens of statements, most of which had been requested months earlier, were handed over about a week ago, when the experts were finishing up the report and could no longer analyse them.
"The speed with which the attorney general's office acted in the last week contrasts with the delays and delays that occurred in the last four months," the report said.