The U.S. Drug Enforcement Administration (DEA) first warned Mexican authorities 16 months ago that plots to break drug lord Joaquin "El Chapo" Guzman out of prison were afoot, documents revealed Monday.

The documents obtained by the Associated Press, show that drug agents first got information in March 2014 that various Guzman family members and drug-world associates were considering "potential operations to free Guzman." A U.S. official briefed on the investigation told the AP that the Mexican authorities were alerted about the plots. The official spoke on condition of anonymity because he was not authorized to disclose details.

Late Monday, Mexico Interior Secretary Miguel Angel Osorio Chong said that authorities were never informed "in that respect," referring to previous escape plans. He added that U.S. counterparts also said they didn't know where the escape information in the AP story came from.

Guzman had been captured in February 2014 at a Mexican seaside resort, and plans to free him began to form almost immediately.

Since the 1990s Guzman's violent and powerful cartel has been known for digging sophisticated smuggling tunnels under the U.S. border with Mexico. The man known as "El Chapo" was first arrested in 1993 but escaped in Jalisco from one of Mexico's top-security prisons in January 2001, allegedly by hiding in a laundry basket. He evaded capture in early February 2014 through an elaborate network of tunnels that connected multiple safe houses in Culiacan, in his home state of Sinaloa, and was arrested again two weeks later.

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Jim Dinkins, the former head of Immigration and Customs Enforcement's Homeland Security Investigations unit said that Guzman's history of tunneling makes Saturday's escape "really ingenious." The sophisticated tunnel described by Mexican authorities would usually take about a year and half to two years to complete, Dinkins said, suggesting it was started almost immediately after Guzman's arrest in 2014.

The DEA documents obtained by the AP do not include details of how the previous escape plots would be carried out. In them, Guzman is identified as Guzman-Loera.

DEA agents did not have information about Saturday night's plan, when Guzman escaped through an underground tunnel in his prison cell's shower area, allegedly built without the detection of authorities. It allowed Guzman to do what Mexican officials promised would never happen after his re-capture last year -- slip out of one of the country's most secure penitentiaries for the second time.

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.

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 has offered its full support to Mexico. He pointed out that Guzman has also been charged with serious crimes in the U.S.

State Department spokesman John Kirby said Guzman's "swift recapture by Mexican authorities is a priority for both the Mexican and the U.S. governments."

The documents revealed that in March 2014 agents in Los Angeles reported a possible escape operation funded by Rafael Caro-Quintero, who helped orchestrate the 1985 kidnapping and murder of DEA agent Enrique "Kiki" Camarena. That plot involved threatening or bribing prison officials. The same investigation revealed four months later that Guzman's son had sent a team of lawyers and military counter-intelligence personnel to design a break-out plan.

In December of that 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."

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.

Guzman's arrest in 2014 was considered a crowning achievement of Mexican President Enrique Pena Nieto's government in its war against drug cartels.

"All the accolades that Mexico has received in their counterdrug efforts will be erased by this one event" if Guzman is not recaptured, said Michael S. Vigil, a retired DEA chief of international operations.

Along with the 2014 escape plans, the DEA documents 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.

The Associated Press contributed to this report.