A judge in New York has denied a request by convicted Mexican drug lord Joaquín Guzmán, known as "El Chapo", to be allowed to exercise outdoors two hours a week.
The judge argued the request could be a ruse by Guzmán to try and escape from his New York jail.
Guzmán escaped twice from maximum security prisons in Mexico.
He was found guilty of drug trafficking in February and is due to be sentenced on 25 June.
'Cruel and unusual punishment'
Guzmán is being held in solitary confinement at a high-security prison in Manhattan, where he was taken in January 2017 after Mexico extradited him to face charges of trafficking huge amounts of cocaine, methamphetamines and heroin to the US.
His lawyer argues that the conditions he is held under are "unnatural and inhumane"; he is only allowed to exercise one hour per week in another indoor cell.
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In a letter, the lawyer said her client had not had access to fresh air or natural sunlight in the more than two years he had been detained.
Prosecutors said the only outdoor exercise area at the prison was located on the rooftop.
The area - which is covered by wire fencing - was the site of an escape attempt in 1981, when accomplices of one of the prisoners commandeered a sightseeing helicopter and tried to spring their friend by ramming it into the fence.
The prosecutors warned of letting "El Chapo" with his history of jail breaks use the facility.
"The defendant has successfully planned and executed elaborate escapes from two high-security penal institutions. As detailed at trial, one of the defendant's escapes involved the construction of a sophisticated, ventilated tunnel that stretched for over a mile. Certainly, an escape via rooftop, using a helicopter, or any related means would be elementary by comparison," the officials said.
The judge also denied a request by "El Chapo" to be given ear plugs to lessen the noise of the air conditioning, arguing that they could make it hard for him to hear the guards' commands in the case of an emergency.
In a separate development, Guzmán's 91-year-old mother said on Saturday that she had been granted permission to travel from Mexico to the US to visit her son.