Documents from the investigative files obtained by journalist Anabel Hernandez suggest that contrary to the government's claims, the drug lord's escape shouldn't have been a surprise.
Guzman's July 11 breakout from a maximum-security prison rekindled the drug lord's reputation as the most powerful of the bad guys.
A tunnel with lights and ventilation that led to his cell, a modified motorcycle and, according to authorities, no forewarning of the plot left many incredulous.
Now, Hernandez, a reporter for the newsweekly Proceso
, says that the disbelief is not about a brazen escape, but of incompetence or collusion by prison guards.
In an interview Tuesday on CNN en Español's "Conclusiones," Hernandez accused the Mexican government of omitting key pieces of information to the public in the aftermath of the escape.
Hernandez obtained documents from the ongoing investigation that suggest there were warning signs aplenty of a pending escape attempt.
The government allegedly had information as far back as March that Guzman's people were looking for blueprints of the prison, Hernandez said the documents show. Prisoners told investigators that they complained to prison officials about "excessive noise" that sounded like construction two weeks before the escape, Hernandez said.
And a clip of surveillance video released by the government to show the moment Guzman walked into the shower in his cell and never reappeared isn't the full story, the investigative report said.
According to the documents, the surveillance video had audio where the banging of metal against concrete can be heard, Hernandez said.
"Instead of doing something about it and prevent the escape, the government just let him go," Hernandez said.
Mexican federal officials confirmed to CNN en Español that the information contained in the documents matches official prosecutor investigative files.
The sources cautioned, however, that the documents are simply a collection of the interrogations and that prosecutors and eventually, a judge, will have to draw conclusions from the testimonies.
She described the documents as interviews between investigators and prison inmates, guards and other witnesses.
Mexico's federal attorney general's office declined to comment, citing the ongoing investigation.
In a news conference following Guzman's escape, the head of Mexico's National Security Commission released the surveillance video of inside the drug lord's cell and said that without audio there was nothing to tip off guards to the escape.
"Now these documents show that that wasn't true, that the government hid the audio of that video because, of course, the audio of that video proves that the government has enough information minutes before the escape and didn't want to stop El Chapo," Hernandez said.
A Mexican federal official with knowledge of the investigation told CNN en Español that cameras such as the ones monitoring Guzman's cell are equipped with microphones, and that additional microphones are added with a prisoner of his stature.
The presence of audio raises questions about why an alarm was not sounded earlier, Hernandez said. The alert of Guzman's escape was not initiated until 43 minutes after there were no signs of movement in his cell.
It's unclear whether any surveillance system captured the noise the prisoners said they heard.
The tunnel began with a 50-by-50-centimeter (20-by-20-inch) opening inside the shower of Guzman's cell, officials said. The tunnel stretched for about a mile and ended inside a half-built house.
It's likely the Sinaloa cartel had spent years infiltrating the country's prison system, a Mexican official told CNN. Whoever helped in the plot likely had the architectural plans for the prison that pointed them toward the shower area, the official said.
And this wasn't the first time.
Nicknamed "Shorty" for his height, Guzman already had pulled off one elaborate escape from a maximum-security prison. In 2001, he managed to break free while reportedly hiding in a laundry cart. It took authorities 13 years to catch him -- closing in as he was sleeping at a Mexican beach resort.
The Sinaloa cartel moves drugs by land, air and sea, including cargo aircraft, private aircraft, buses, fishing vessels and even submarines, the U.S. Justice Department has said.
The cartel has become so powerful that Forbes magazine listed Guzman in its 2009 list of "self-made" billionaires. Guzman's estimated fortune at the time was $1 billion.
Guzman has been a nightmare for both sides of the border. He reigns over a multibillion-dollar global drug empire that supplied much of the marijuana, cocaine and heroin sold on the streets of the United States.