DEA knew "El Chapo" had escape plans, warned Mexico

(CBS NEWS)  U.S. officials knew that almost immediately after Mexico's biggest drug cartel chief, Joaquin \"El Chapo\" Guzman, was captured in 2014, plots were being hatched to free him, sources told CBS News.

Drug Enforcement Administration agents had developed bits of information about the various plans, and passed that information along to Mexican authorities, a law enforcement source told CBS News chief investigative correspondent Pat Milton.

However, none of the information was specific to Saturday's successful break-out plan, the source said.

The source said that Guzman's son, his family and confederates were all talking about how to break him out of prison.

There was big concern from day one that there would be attempts to get him out, the source said.

However, Mexico apparently did not take all precautions necessary to protect their most valuable prisoner, who had escaped from prison once before with help.

As CBS News correspondent Omar Villafranca reports, authorities there dismissed widespread concerns about corruption, turned to extradition requests from the U.S., and promised Guzman was secure.

At the time, Eduardo Medina Mora, the former Mexican ambassador to the U.S. said: \"He's locked up in the most reliable prison we have in Mexico and certainly once bitten, twice shy. We will take our precautions in this case.\"

In March 2014, agents in Los Angeles reported a possible escape operation funded by another drug organization run under the auspices of Guzman's Sinaloa Cartel. That plot involved threatening or bribing prison officials. That July, the same investigation revealed that Guzman's son had sent a team of lawyers and military counter-intelligence personnel to design a break-out plan.

In December of the year, agents in the DEA's Houston Field Division reported that a Mexican army general stated \"that a deal was in place to release both Guzman-Loera and imprisoned Los Zetas Cartel leader Miguel Angel 'Z-40' Tevino-Morales.\"

A widespread manhunt that included highway checkpoints, stepped up border security and closure of an international airport failed to turn up any trace of Guzman by Monday, more than 24 hours after he got away.

About 30 prison guards are being held for questioning, Villafranca reported. The U.S. Justice Department is helping with that investigation.

The White House said Monday U.S. Attorney General Loretta Lynch spoke with Mexico's attorney general the day after the escape was discovered. White House spokesman Josh Earnest said the U.S. government is offering its full support to Mexico. He's pointing out that Guzman has also been charged with serious crimes in the U.S.

Widely considered the world's richest and most powerful drug trafficker before his capture last year, Guzman slipped down a shaft from his prison cell's shower area late Saturday and disappeared into a sophisticated mile-long tunnel with ventilation, lighting and a motorcycle apparently used to move dirt.

Former DEA regional director in Mexico David Gaddis told CBS News the case \"goes back to the corruption, the endemic corrupton throughout the Mexican prison systems.\"

\"It's very disappointing, and quite frankly I'm stunned -- although not surprised -- that this happened,\" Gaddis said. \"You cannot take somebody of that caliber in the criminal world and treat them as if they're any run of the mill prisoner.\"

Along with the 2014 escape plans, DEA documents obtained by the Associated Press reveal that Guzman was still directing facets of his drug empire.

\"Despite being imprisoned in a 'high security' facility, DEA reporting further indicates Guzman-Loera was able to provide direction to his son and other cartel members via the attorneys who visited (him) in prison and possibly through the use of a cellphone provided...by corrupt prison guards,\" the documents stated.

Following Guzman's capture, according to the documents, his son Ivan Guzman-Salazar became \"the de facto leader of the Guzman branch of the Sinaloa Cartel.\" Guzman's \"right-hand man, Damaso Lopez-Nunez\" took over one of the four major trafficking organizations that operated under the auspices of the larger Sinaloa Cartel.

It is \"premature to accurately predict\" what will now happen to the power structure of the organization, but Guzman's escape likely \"will affect current leadership,\" according to the documents.

© 2015 CBS Interactive Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.