Guzman Lopez and Ismael "El Mayo" Zambada were arrested last week in a Hollywood-style takedown of the Sinaloa cartel leaders.
For now, Zambada remains held in custody in Texas, where he and Guzman Lopez were arrested. El Chapo's 38-year-old son has already been moved to Chicago.
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Zambada's attorney claimed over the weekend that his client was tricked into flying into the country, saying he was "forcibly kidnapped" by Guzman Lopez.
El Mayo, as he is known, was already a wanted fugitive in Chicago with a $15 million bounty on his head. Allegedly, Guzman Lopez convinced the elder cartel boss to board a plane for an airstrip inspection in northern Mexico. Instead, they kept flying into the U.S, where they were arrested by drug agents.
But Zambada's attorney said it's not true. Dallas lawyer Fran Perez, who has represented other cartel clients in Chicago, claims Zambada was "forcibly kidnapped" by Guzman Lopez, "ambushed, thrown to the ground, and handcuffed by six other men in military uniforms."
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Perez said Zambada's legs were tied and a black bag placed over his head before he was drive to the plane and flown to the United States.
"They ended up landing in Texas, and they were greeted by the FBI and agents from the department of homeland security, homeland security investigations. It was an extraordinary turn to get these men to basically to fly into the United States and be arrested by U.S. agents," said Jack Date, ABC News Senior Justice and Homeland Security Reporter
As Guzman prepared for a high-security initial court appearance at Chicago's Dirksen Federal Building, there are still questions about how the arrests actually went down.
Mexican authorities have their own version; the nation's security secretary said El Chapo's son turned himself in to American officials last week. U.S. law enforcement leaders apparently knew Guzman was considering a surrender and found out it was happening once the plane was in the air, according to Mexican officials.
Guzman Lopez is due in court Tuesday.