Mexico City – There’s no evidence to support the Mexican government’s claim that 43 students who went missing last year were burned at a landfill, a group of international experts said in a report released Sunday.

That has been a key part of Mexican authorities’ public pronouncements about the controversial case, which drew global attention to the country’s struggles with violence and corruption and sparked protests nationwide.

Sunday’s report by independent experts from the Inter-American Human Rights Commission left top Mexican officials backpedaling on claims the government made last year, when Mexico’s then-attorney general announced the bodies of the students had been burned.

After the new report’s release, Attorney General Arely Gomez Gonzalez said Sunday that Mexico would launch a new investigation at the landfill site.

“We will request a new investigation led by a group composed of forensic investigators of the highest prestige,” she said, adding that the report was conducted at the request of Mexican officials seeking help on the case.

But she also pointed out that another key aspect of the Mexican government’s investigation was confirmed by the independent report: the involvement of corrupt local police and the mayor in the students’ disappearance.

Gomez didn’t take questions after her Sunday news conference, and it wasn’t clear whether Mexican authorities were reconsidering other conclusions they’d previously drawn about the case.

More than 11 months after 43 students went missing during a night of violence in Iguala, Mexico, remains of just one of them have been positively identified. Authorities have said the remains of all of the students were dumped into a river but were so badly burned that it’s impossible to identify the others.

Mexico’s government has officially declared them dead.

In a statement Sunday, a top official from Amnesty International said the new report shows Mexican authorities need to refocus their investigation — and fast.

“Mexico is living one of its worst human rights crises in decades,” said Erika Guevara-Rosas, Americas director for the group. “The catalog of failures in the search and investigation into the disappearance of the 43 students that the group of experts have denounced is an enormous stain on the reputation of the Mexican government, which can only begin to recover if those responsible are found.”

Mexican President Enrique Peña Nieto posted a series of tweets Sunday saying he’d ordered his government to analyze the report’s recommendations.

Gomez vowed that authorities won’t rest until they’ve gotten to the bottom of what happened to the students.

“The federal institutions are responsive and are acting decisively in the face of these unfortunate events,” she said.

Families of the missing students have long said they didn’t believe the government’s explanation of the case and have continued protests for months.

Their search for their loved ones won’t stop until they get answers from the government that they can believe, Melitón Ortega, whose son is among the missing, told CNNMexico in July.

“Even though politicians and authorities ask us to accept that our 43 students were killed,” he said, “we will keep looking for them alive as long as what happened is not explained with irrefutable scientific proof.”

As reported by CNN