It has been almost two years since the 43 students from Ayotzinapa mysteriously disappeared in the state of Guerrero.

“With firm determination, the Mexican government will maintain its efforts to obtain total clarity about the facts,” said Mexico President Enrique Peña Nieto during a press conference in November 2014.

He continued, “The capture of the intellectual authors is not enough, we will detain everyone who participated in these abominable crimes. To the parents of the missing students and the Mexican society altogether, I assure you, that I will not stop until justice prevails.”

During a recent interview with Jorge Ramos on “Al Punto,” Claudia Paz and Francisco Cox, members of the Grupo Interdisciplinario de Expertos Independientes (GIEI), revealed that the Mexican government was a huge obstacle during their investigation about the happenings.

“Unfortunately, there was no political effort to give us full access to the sources,” said Paz. “We had no access to the people being accused in the case. This was very important in order to be able to dig deeper, and come up with possible conclusions about the whereabouts of the students.”

Official reports about the investigation suggested that the victims were incinerated and their ashes were thrown into the river. GIEI investigators, however, say that information is false.

“We haven’t been able to determine the final destination [of the students],” said Cox. “What we know is that the 43 students were not burnt in Cocula’s dump, as official reports informed. And unfortunately, due to diverse obstacles that we had to deal with during our investigation process, we couldn’t go any further.”

Cox added that the government seemed to be willing to cooperate with them for the first six months, but thinks rapidly changed when state officials were linked to the crime.

“What we saw was a very strong change in everyone’s attitude,” he revealed. “A new team was created, which was one of the things we suggested. However, after a short period of time, we realized that the old team, the investigation agency that had previously reported the wrong version of the facts, was still calling the shots. That’s when we started encountering all these obstacles.”

Paz and Cox’s investigation was stopped after they publicly contradicted official reports. Click on the video below to watch the full interview.