Independent experts investigating the disappearance of 43 students in Mexico have threatened to stop working with government authorities, accusing them of manipulating the probe for political ends.
The group of experts was charged by the Inter-American Commission on Human Rights with investigating the ambiguous disappearance of students in the southern city of Iguala in September 2014.
"The group will not continue collaborating on this case if the process does not adhere to the terms agreed and international standards and only adds to the confusion and discredit," said Claudia Paz, the former attorney general of Guatemala and a member of the team.
The backlash occurred after prosecutors published what Paz called a "preliminary" report on an analysis of whether the students' bodies were burned at a garbage dump, as the Mexican authorities claim.
The report, the third forensic analysis of the possible crime scene, found that at least 17 bodies were burned at the dump.
But Paz told a press conference that releasing it unilaterally amounted to "political use" of findings which appear to support the Mexican authorities' version of events.
The independent experts said they are still waiting for an analysis of the amount of combustible material that would have been used to burn so many bodies.
Prosecutors say police handed the 43 students over to members of a drug cartel, who killed them, incinerated their bodies and tossed the remains into a nearby river.
But independent experts and Argentine forensic investigators have said there is no scientific proof that a large fire was set at the dump.
Forty-three student from the Ayotzinapa Teacher Training College were kidnapped on the night of Sept. 26, 2014 by the police in the city of Iguala, in Guerrero. The police then handed over the students to United Warriors, a local gang.
So far, the remains of only one of the missing students has been positively identified and the whereabouts of the rest remain a mystery.