Guzman, Mexico`s most infamous kingpin, slipped through a hole under the shower and escaped through a mile-long tunnel to freedom, authorities said.
And the newly released closed-circuit video shows how calmly and easily he did it.
Mexican Interior Minister Miguel Ángel Osorio Chong said Guzman`s cell was videotaped 24 hours a day. But the surveillance system had two blind spots that Guzman exploited.
Guzman also had a bracelet that monitored his every move, the interior minister said. But he left the bracelet behind before he crawled into the tunnel and made his getaway.
Dozens questioned; prison officials fired
At least 49 people have been questioned in connection with the escape, a Mexican official said. And Mexico`s interior minister said Monday that he has fired the prison director and other prison officials.
It`s likely prison workers helped Guzman break out, the interior minister told reporters.
As Mexican authorities announced the reward for his capture Monday night, they released what they said was a recent picture of Guzman, showing him with a shaved head and face.
Guzman wasn`t sporting his trademark mustache, the one he had when authorities captured him last year in what was considered on both sides of the border to be a major law enforcement victory.
Did DEA know of past plots?
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.
U.S. officials are fuming over the fact he broke out of prison again. When he was arrested in Mexico last year, the United States asked to have him extradited, in part because of concerns he would escape.
At some point following his recapture, U.S. Drug Enforcement Administration agents received information suggesting relatives and associates were looking for ways to break Guzman out of prison, a law enforcement official told CNN Tuesday.
The officials had no specific details about an escape but, as is routine, passed along what they knew to Mexican authorities, the official said.
Osorio Chong denied the government was notified.
How he did it
Guzman took a sophisticated route during his escape, officials believe: a tunnel complete with lighting, ventilation and even a modified motorcycle on tracks "that was likely used to remove dirt during the excavation and transport the tools for the dig," Mexican National Security Commissioner Monte Alejandro Rubido said.
The tunnel began with a 50-by-50-centimeter (20-by-20-inch) opening inside the shower of Guzman`s cell, Rubido 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.
`A complete savage`
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.
The U.S. Justice Department describes the Sinaloa cartel as "one of the world`s most prolific, violent and powerful drug cartels." It says Guzman was considered the world`s most powerful drug lord until his arrest in Mexico in February 2014.
"He is a complete savage," CNN law enforcement analyst Tom Fuentes said. "What they do, and how they do business, is based on complete terror. ... They kill journalists, politicians, police officers, corrections officers. And then not just that person, but every member of their family."
The Sinaloa cartel moves drugs by land, air and sea, including cargo aircraft, private aircraft, buses, fishing vessels and even submarines, the 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.
