MEXICO CITY (Reuters) - Mexico’s human rights commission blasted the government’s investigation of the 2014 disappearance of 43 students for a long list of failures, adding the remains of 19 unidentified people were found in a trash dump linked to the case.

Luis Gonzalez, the head of Mexico’s human rights commission, told a conference late on Wednesday that burnt remains were found in a dump where government prosecutors said the 43 trainee teachers’ bodies had been burnt by gang members who killed them.

Independent international investigators have cast serious doubts on a government version of events that said the students were taken to the dump and burnt there, and Gonzalez cautioned the remains had not yet been identified as any of the missing students.

He noted the dump had been a used by local gangs to dispose of bodies for some time.

The abduction and suspected massacre of the trainee teachers in the southwestern city of Iguala sparked one of the worst crises of outgoing President Enrique Pena Nieto’s government.

President-elect Andres Manuel Lopez Obrador has promised to quickly launch a truth commission to get to the bottom of what happened to the students.

The case became emblematic of a surge in violence and corruption during Pena Nieto’s presidency that fed the landslide victory of leftist Lopez Obrador, who takes office on Saturday.

Family members of the students have refused to accept the government’s version.

Gonzalez criticized the government’s investigation for “grave human rights violations” and said it would be up to the incoming government to clear up the case and file charges.

The U.N. human rights office said in a report in March that Mexican authorities had tortured dozens of people during the investigation.