A group of Argentine forensic experts says it has determined there's no biological or physical evidence to conclude that 43 students who disappeared in southern Mexico in 2014 were incinerated at a trash dump as government investigators initially claimed.
The report released Tuesday by the Argentine Forensic Anthropology Team signaled that the dump in Cocula, Guerrero state, was the site of multiple fires at various times, but while the remains of at least 19 people were found near there, there's no evidence they belong to the missing students.
The government has said the students were killed by a drug gang, their remains incinerated, and their charred bone fragments gathered up and tossed in bags in a nearby river. Some of those bone fragments have been linked by DNA testing - in one case positively, and in another case, tentatively - to two of the missing students.
But because the forensics team was not present when a bag containing the fragments was recovered, they cannot vouch that those fragments came from the dump. The team also said that largely undamaged plants found at the supposed site of the pyre would have been killed or been severely damaged by a fire of such intensity.
It is the second independent report to reject the Mexican government's main finding from a little over a year ago about what happened to the students, who were taken by police in the nearby city of Iguala on Sept. 26, 2014, and allegedly handed over to local members of a drug gang for slaughter. They remain missing.
In September, experts from the Inter American Commission of Human Rights said a separate independent forensic investigation established that they could not have been burned at the dump.
The students' disappearance attracted local and international opprobrium and has been a stain on the government of President Enrique Peña Nieto.
After the commission's report, the government announced it would launch another forensic analysis of what happened at the dump, though that has not yet taken place.
The Argentine experts' investigation spanned more than a year and examined diverse elements found at the site, from human remains to plants, excrement, insects, rocks, glass, bullet shells and tires. It also incorporated satellite imagery.
The report concluded that while there had been multiple fires there over the course of years, none was large enough to have burned 43 bodies.
In 2015, then-Attorney General Jesus Murillo Karam claimed that his investigators had arrived at a "historic truth" about what happened to the students: that they were killed by drug gang members, burned at the dump and their ashes put into sacks and thrown into a nearby river.