Mexican President Andres Manuel Lopez Obrador confirmed on Thursday that a witness implicated soldiers in the 2014 disappearance of 43 students in the southern state of Guerrero that rocked the country.The attack on the trainees from the Ayotzinapa Rural Teachers' College on Sept. 26, 2014 sparked widespread protests across the country.The witness, known as "Juan," said soldiers detained a group of the students, interrogated them at the army base in the town of Iguala and then handed them to a drug gang, according to a copy of his testimony reported by newspaper Reforma.Former defense minister Salvador Cienfuegos, recently arrested on U.S. drug charges that were later dropped, long refused to allow investigators access to soldiers at the base over their possible involvement in the massacre.The witness said members of the Guerreros Unidos gang hacked up some of the students with machetes and took their remains to a crematorium controlled by the gang, while others were dissolved in acid, Reforma reported.Evidence was sown at a rubbish dump, the witness said, to support a narrative being pushed by the federal government at the time.The witness' testimony is included in the attorney general office's investigation of the case.Lopez Obrador confirmed Reforma's reporting reflected the testimony in the investigation."What Reforma published is in the prosecutor's file. I don't know how they got it, but it's real," said Lopez Obrador. He cautioned that the accusations were based on only one witness."We can't say that this is what happened," he added, during a regular news conferenceThe witness said military commanders and police took bribes from Guerreros Unidos. His testimony also implicated Mexico City's police chief, who recently survived an assassination attempt.The chief, Omar Garcia Harfuch, at the time worked in Guerrero. On Thursday he "categorically denied" the allegations, saying he had nothing to hide.Lawyers for the student's relatives expressed concern the investigation could be compromised by the leak of witness testimony.