Two of Guzman's lawyers gave an indignant press conference yesterday outside his maximum-security prison after they were not allowed to visit their client and bring him clothes and other personal items.
Lawyer Juan Pablo Badillo said he feared for Guzman's health and safety.
"There's a growing fear (among Guzman's lawyers) that something may happen to him, because it's suspicious that they won't even let his defense attorneys look at him, ask him how he's feeling, what he's been through, whether he's been tortured," he said.
Guzman, the kingpin of the powerful Sinaloa drug cartel, escaped from the same prison outside Mexico City on July 11.
He was recaptured a week ago after six months on the run and sent back to prison -- this time with two tanks posted outside and heavily beefed-up security measures.
Interior Minister Miguel Angel Osorio Chong denies Guzman has been refused access to his lawyers, saying he met with one on Tuesday.
"Not even if they had caught Adolf Hitler alive would they have done to him what they are doing to Mr Guzman," he said in a radio interview earlier this week.
Guzman was being held under "extra security conditions," Renato Sales, Mexico's National Security commissioner, told Radio Formula.
The government earlier said that "El Chapo" is in a section of the prison where the most dangerous criminals are held -- the same area where he escaped from in July.
Sales however said that this time Guzman is being held in a different wing, and that all the nearby cells are empty. Agents shuffle the fallen drug lord in an unscheduled manner between the different cells.