Federal police and soldiers are seen at a checkpoint in Mexico City, on July 13, 2015 during the hunt for escaped drug kingpin Joaquin "El Chapo" Guzman
Almoloya de Juárez (Mexico) (AFP) - Mexican security forces scrambled Monday to save face and recapture drug kingpin Joaquin "El Chapo" Guzman as authorities investigated whether guards helped him escape prison through a tunnel under his cell.
For the second time in 14 years, the head of the powerful Sinaloa drug cartel managed to flee a maximum-security prison, dealing an embarrassing setback to President Enrique Pena Nieto.
Troops and police manned checkpoints and hunted for Guzman after he vanished late Saturday from the Altiplano prison 90 kilometers (55 miles) west of Mexico City, after just 17 months behind bars.
Prosecutors have questioned more than 50 people so far.
A federal official said 32 prison employees of various rank, including the warden, spent the night at the anti-organized crime unit of the attorney general's office, but no charges have been filed so far.
The guards in charge of the capo's cell and those who monitored the surveillance cameras that look into the room were among those interrogated.
"They are making statements, with the assistance of lawyers and human rights personnel," the official from the prosecutor's office told AFP on condition of anonymity.
Prosecutors also spoke with 17 inmates at the prison.
Two of Guzman's lawyers were questioned and anybody else who visited him during his incarceration is being sought, the official said.
Authorities had already investigated a strange prison visit to Guzman in March when a woman managed to see him by using a fake ID to enter the jail.
Another person being sought for questioning is the owner of the property where Guzman's 1.5-kilometer tunnel ended.
"It's an important piece to know if (the property) was sold or rented, and to whom," the official said.
Guzman, 58, who nurtured a Robin Hood image in his northwestern state of Sinaloa while running the most powerful and one of the most ruthless cartels in Mexico, was able to slip out even though surveillance cameras were trained on his cell.
He went into his private shower and after he failed to come out, guards found a hole 10 meters (33 feet) deep with a ladder inside.
The gap led to a sophisticated tunnel with a ventilation and light system that ended inside a gray brick building on a hill surrounded by pastures in central Mexico State.
A huge water pipeline project is under construction around the prison, which could explain why the tunnel's construction went unnoticed.
- Against the clock -
As investigators tried to figure out how Guzman busted out again, police and troops manned checkpoints and searched cars and trucks on nearby roads.
The US State Department said Guzman's "swift recapture by Mexican authorities is a priority for both the Mexican and the US governments."
Mike Vigil, a retired US Drug Enforcement Administration (DEA) international operations chief, warned that if Guzman is not captured in the next day or so he will vanish for good.
"If he is able to make his way to Sinaloa, his native state, and gets into that mountainous range, it's going to be very difficult to capture him because he enjoys the protection of local villagers," Vigil said in an interview.
Several states, including Sinaloa, set up checkpoints. Central Puebla state said it was using X-ray technology at toll booths to see through cars.
Security forces in Central American nations were placed on high alert at their borders. It was in Guatemala that Guzman was first arrested in 1993.
- Problem with US? -
Guzman's first escape was in 2001, when he slipped past authorities by hiding in a laundry cart in western Jalisco state.
Marines recaptured him in February 2014 in a pre-dawn raid at a condo in Mazatlan, a Pacific resort in Sinaloa state, with the DEA's help.
The government has won praise for capturing a slew of kingpins, and Guzman -- a diminutive but feared man whose nickname means "Shorty" -- was the president's biggest trophy.
Some US prosecutors wanted to ask for his extradition following last year's arrest, but Mexican officials insisted on trying him first.
"This leads to a big problem with the US government because they asked (for an extradition) and the Mexican government did not deliver him, claiming that he could be held in one of the country's maximum-security prisons," said Raul Benitez Manaut, a security expert at the National Autonomous University of Mexico.