The amazing testimony came from Alex Cifuentes, a Colombian trafficker who once served as Guzman's secretary and close personal assistant.
After three days at the stand in the federal courtroom in Brooklyn, the bombing revelation was only brought in court by defense lawyer Jeffrey Lichtman, not prosecutors.
Cifuentes had witnessed two years spent with Guzman in the mountains of Sinaloa when the fleeting kingpin removed the army.
While previous testimonies involved lower Mexican politicians as well as police and military officials in the large corruption network that facilitated Guzman's cartel trade, Tuesday's accounts struck at the highest level of Mexican political life.
There is the possibility that jury members may hear from Guzman even during the trial ̵
Details of the alleged bribe
During cross-examination by defense lawyer Lichtman, who referred to the transcripts of the briefings, Cifuentes had argued with US authorities that Cifuentes had claimed that a 100 million dollar bribe was paid to Peña Nieto, who was president from 2012 to 2018.
In opening statements in November, Lichtman claimed that Peña Nieto and former presidents of Mexico "received hundreds of millions of dollars in bribes from his organization."
A spokesman for Peña Nieto at that time refused the accusation in a statement posted on Twitter.
"Enrique Peña Nieto's government pursued, captured and handed over the criminal Joaquin Guzman Loera," the government said. "The accusations of his lawyer are completely false and defamatory."
On Tuesday, Lichtman asked Cifuentes for statements he made to US officials in November 2017 when he claimed that the former president had allegedly contacted Guzman to say he "didn't have to keep himself" if he paid the money.
Cifuentes told the authorities that the money was given to Peña Nieto in October 2012 when he was presidential.
"Yes, that's what Joaquin told me," Cifuentes replied, adding that a bribe would ensure that kingpin could "continue to work."
Cifuentes said in three separate meetings with the US authorities in 2016 and 2017 that $ 100 million was paid to Peña Nieto. In a meeting in September 2018, his story was changed. He told prosecutors that he had been confused about the exact amount.
On Tuesday, he testified that he was "confused" about the exact amount of bribes.
In a debriefing with the United States, Lichtman Cifuentes told the US authorities that a woman working for political strategist JJ Rendon sent testimonials of suitcases filled with cash inside Rendon's personal plan. Rendon ran Peña Nieto's campaign at the time.
Cifuentes said he thought photographs of cash-filled suitcases were taken in Mexico City.
Rendon denied Cifuente's allegations in an interview with CNN Español on Tuesday and said he was willing to be investigated for them.
Lichtman also asked Cifuentes another claim he made to US authorities in 2016: former President Felipe Calderón received bribes from a rival drug trafficking.
In November, Calderón refused to ever receive any payments. "The allegations of Joaquin & # 39; El Chapo & # 39; Guzman's lawyer are completely false. Neither he nor the Sinaloa cartel or anyone else made any payments to me," he wrote on Twitter.
In court Tuesday, cifuentes said he did not recall this episode.
Cifuentes, who described himself as Guzman's "right hand, his left hand", had testified earlier Tuesday that Guzman had attempted to receive a $ 10 million bribe to another senior Mexican official, but was rejected because Officially disliked Guzman.
Cifuentes faced his former boss on Thursday and shared details of Guzman's commercial transactions and how the leader of the Sinaloa cartel escaped the authorities in a number of remote mountain ranges in his homeland.
Cifuentes was arrested in Mexico in 2013 and later extradited to the United States, where he allegedly was guilty of drug trafficking and entered into a cooperation agreement with the US Government.
Guzman, 61, has claimed guilty. If he is convicted of international drug trafficking, mingling to kill rivals, gunfire and money laundering, he is facing a prison sentence.
In 2017, Guzman was handed over on a flight from Juarez, Mexico to New York.