An official government account of the disappearance of 43 students that sparked a wave of public outrage in Mexico is scientifically impossible, according to an investigation by independent experts assembled by the Inter-American human rights commission.

The six-month investigation also highlighted numerous other doubts about the government’s version of events surrounding the incident on 26 September last year that left six people dead as well as the 43 disappeared.

The Mexican government said that the students were killed and incinerated in a rubbish dump because they were mistaken for members of a drug gang. However, the 500-page report released on Sunday underlines the inconsistent and at times contradictory confessions of detainees, who have since claimed they were victims of torture, as well as questions the justifications given by the federal authorities for not acting to stop the attacks.

“This report provides an utterly damning indictment of Mexico’s handling of the worst human rights atrocity in recent memory,” said José Miguel Vivanco, director of the Americas division at Human Rights Watch.

“Even with the world watching and with substantial resources at hand, the authorities proved unable or unwilling to conduct a serious investigation.”

Months of protests, many led by the parents of the missing students and sometimes including outbreaks of violence, lead to the collapse of president Enrique Peña Nieto’s international image as a moderniser.

They underlined both the continued horror of Mexico’s drug wars that had been consistently downplayed by his administration and the entrenched political corruption that provided a backdrop to much of the terror, as well as the government’s clumsy and insensitive handling of its investigation.

The students came from the famously rebellious teacher training college of Ayotzinapa, about 90 minutes drive from Iguala in another part of the same state, Guerrero. They had made the journey in order to commandeer buses to use in a later protest.

Under pressure to respond to the demands for their reappearance, the then attorney general, Jesús Murillo Karam, unveiled in early November what he said was the historical truth of what had happened.

He said municipal police from Iguala and the neighbouring municipality of Cocula, working in coordination with a local drug gang known as Guerreros Unidos, had attacked the students as they sought to return to Ayotzinapa in the busses probably because they suspected they were linked to a rival drug gang known as Los Rojos.

He said the police had handed the students over to members of Guerreros Unidos who had taken them to a rubbish dump outside Cocula where they were killed and burned on a pyre, before their remains were collected in plastic bags and dumped in a river.

The government sent the only bone fragments found that it said could still contain traces of DNA to a specialised laboratory in Austria, that later identified one of them as belonging to Alexander Mora. He remains the only one of the missing students who has been officially declared dead.

Sunday’s report cites numerous inconsistencies in the official version and questions the idea that the students could have been mistaken for rival drug traffickers, suggesting that it could be more fruitful to explore the hypothesis that the students may have unwittingly commandeered a bus that was being used to smuggle opium paste.

“All the attacks against the students were directed at stopping the buses leaving Iguala,” Carlos Beristain, one of the experts, told a press conference on Sunday. “This should be investigated as a possible motive for the attacks.”

But the biggest impact of the report is its inclusion of a scientific study of the funeral pyre carried out by an expert based in Australia.

In the government’s version, five gang members built and maintained the pyre for a maximum of 16 hours with the help of limited amounts of tyres, plastics, wood and fuel.

The study concluded it would have required 30,000kg of wood or 13,330kg of rubber tyres and burned for 60 hours in order to consume the bodies. It adds that feeding the pyre would have been impossible, and that a conflagration of those dimensions would have left obvious evidence in the surrounding area, which an inspection of the site failed to find.

“We maintain the conviction that the students were not incinerated in the Cocula rubbish tip,” said another of the report’s authors, Francisco Cox.

The report also highlights that the pyre version is based on the confessions of the five alleged members of Guerreros Unidos, currently among over 100 people detained in the government’s investigation.

All five told the experts that they had been tortured and a revision of government medical reports of detainees detail numerous wounds consistent with that claim.

The report also undermines the federal government’s efforts to entirely blame the events on local corruption, and claims that the federal forces did not have the necessary information to prevent the killings.

But the experts’ revision of witness statements and official logs found that state and federal forces were monitoring the students movements from the moment they left their college, as well as the development of the attacks in Iguala.

Following the release of the report, Attorney General Arely Gomez pledged to incorporate its findings into the government’s investigation, and said she would be ordering a new high level technical study into the incineration hypothesis.

In a brief press conference on Sunday, in which she took no questions, Gomez did not mention the other potentially devastating doubts about the official version, such as the weight given to questioned confessions or the evidence that the federal authorities were monitoring the events. She stressed, instead, that the report backs the government investigation’s focus on the municipal police and their infiltration by organised crime.

“The disappearance of the students in Iguala has angered and hurt all society,” Gomez said. “The victims and their relatives can rest assured that all those involved will be detained.”

At a packed and emotional press conference, parents of the students held up photographs of their missing children, and expressed both anger and hope at the report that confirmed their earlier rejection of the official version that government officials had put down to grief.



“It was a vile lie that they were burned in the Cocula rubbish tip,” Emiliano Navarrete, father of Jose Angel Navarrete, cried, as he shouted into the microphone. “It wasn’t that we were unable to accept the truth, it was that there was no evidence.”

Navarrete and other parents demanded a face-to-face meeting with the president, prosecution of the public officials responsible for the investigation, and asked for massive public support for the demonstration planned to mark the first anniversary of the events in 20 days time.

“The government’s farce has collapsed, and the question is where are our children” said Mario Cesar Gonzalez, father of Cesar Manuel Gonzalez, “We demand that they are returned alive.”