Federal prosecutors think Joaquín "El Chapo" Guzmán is planning his escape as his defence team had several unusual prison requests. Picture: United States Drug Enforcement Administration via AP

Washington - For two and half years, Mexican drug kingpin Joaquín "El Chapo" Guzman has lived in solitary confinement-with nearly no ability to communicate with the outside world.

Now, with Guzman allegedly showing symptoms of distress and sleep deprivation, his defence team had several requests for US District Judge Brian Cogan earlier this month: two hours of outdoor exercise every week, the same food and drink as other inmates, permission to buy six bottles of water a week and earplugs.

"This deprivation of sunlight and fresh air, over an excessive 27-month period, is causing psychological scarring," CNN reported the letter said. It called the conditions "cruel and unusual punishment" in violation of the Eighth Amendment.

Federal prosecutors were not convinced.

According to new court filings obtained by CNN, the government opposed all of the above and alleged the request was part of a ploy to escape from prison or silence cooperating witnesses.

Jeffrey Lichtman, one of the lawyers on Guzman's defense team, called the prosecution's response, due Thursday, "literally hysterical."

The high-profile prisoner has had no prison infractions since his arrest, he said, "yet now, by simply asking for some bottled water and some fresh air he is accused of plotting a daring prison escape despite zero supporting evidence."

In February, federal prosecutors secured a conviction against the Sinaloa Cartel boss for running the drug trafficking enterprise. During the three-month trial, witnesses - including his former bodyguard - testified about horrific murders both ordered and carried out by Guzmán. On one occasion, he allegedly shot the rival-cartel member and then buried the victim alive.

Guzmán, 61, faces multiple life sentences; he will be sentenced in federal court June 25.

Until then, the government requested Guzman be held in restrictive detention.

"I expect the Bureau of Prisons would be concerned about El Chapo's communication access; his phone calls, email access and letters are likely to be more closely monitored than the average prison there for federal drug possession," Deborah Golden, staff attorney at the Human Rights Defense Center, told The Washington Post in February. Indeed, Guzman's conviction led to widespread speculation he would be housed at ADX, the administrative super-maximum prison in Florence, Colorado.

Guzmán's requests are being scrutinized because he has broken out of prisons in the past. He escaped from two maximum-security Mexican prisons - in 2001 with the assistance of prison guards and in 2015 through a tunnel underneath the shower in his jail cell.

"An escape via rooftop, using a helicopter, or any related means would be elementary by comparison," the prosecutor wrote in his response to the court. Adding to the government's concern is the unsuccessful, attempted jail break in 1981, where an inmate arranged a helicopter-escape from the recreation area of a Lower Manhattan prison.

The defence has a week to reply.

Guzman is not permitted to have unmonitored phone calls or receive mail, Lichtman said, and his attorneys are the only people he can communicate with.

"Because an inmate once attempted to escape the MCC 30 years ago via helicopter, Joaquin Guzman is planning the same?" he quipped on Saturday. "Which one of his lawyers passed the message to his co-conspirators to plan this escape?"

The Washington Post