NEW YORK (CBSNewYork/AP) — An official with Amnesty International wants to interview Mexican drug lord Joaquin “El Chapo” Guzman about allegations he’s being mistreated in the high-security wing of a federal jail in Lower Manhattan that’s housed mobsters and terrorists.

The human rights group is “concerned that the conditions imposed on (Guzman) appear to be unnecessarily harsh and to breach international standards for humane treatment,” Justin Mazzola wrote in a letter to federal prosecutors in Brooklyn, where the U.S. case against Guzman was brought.

READ MORE: Suffolk Police: Franklyn Charles, 18, Charged In Crash That Killed Jennifer Figueroa, 30, In Wyandanch

Mazzola is seeking access to the Metropolitan Correctional Center amid reports that Guzman’s health has deteriorated since he was brought to the United States in January to face charges that he oversaw a multibillion-dollar international drug trafficking operation responsible for murders and kidnappings.

The U.S. attorney’s office declined to comment Thursday.

Amnesty International’s request follows complaints by Guzman’s lawyers about conditions in the Special Housing Unit — known by its acronym, the SHU, pronounced like “the shoe” — where prisoners spend 23 hours a day in 20-by-12-foot cells, prohibited from communicating with one another.

In the past, the unit has held other high-profile, high-risk inmates like Gambino crime family boss John Gotti and several former close associates of Osama bin Laden.

In court papers, the defense has claimed an anxiety disorder that began during Guzman’s imprisonment in Mexico has worsened to the point where he “has difficulty breathing and suffers from a sore throat and headaches.” It also said he’s experiencing “auditory hallucinations, complaining of hearing music in his cell even when his radio is turned off.”

The government has argued that the conditions are appropriate for someone who escaped twice from prison in Mexico, including once through a mile-long tunnel dug to the shower in his cell. Prosecutors said that even while he was behind bars in Mexico, Guzman used coded messages, bribes and other means to control his Sinaloa cartel and orchestrate his breakouts.

READ MORE: Alec Baldwin Was Told Gun Was "Cold" Before Fatal Movie Set Shooting, Court Records Show

An examination by a jail psychologist, the prosecutors added, revealed that the defendant was hearing a radio played by a staff member. The back-and-forth over the radio continued in the latest defense filing, with lawyers responding that “unless that radio was playing Mexican music, Mr. Guzman is hearing non-existent sounds.”

In a statement, Amnesty International called the request to see Guzman routine, given its history of advocating for the rights of prisoners held in solitary confinement.

“Under this line of work, we have monitored the situation of that Manhattan facility for years, and will continue to do so,” it said.

Guzman, 59, was brought to the United States in January to face charges that he oversaw a multi-billion dollar international drug trafficking operation responsible for murders and kidnappings.

He appeared in a federal court in Brooklyn last month under heavy guard, arriving with an unprecedented security entourage of more than a dozen vehicles and a police chopper overhead.

He is due back in federal court on May 5.

MORE NEWS: Campaign 2021: Early Voting Begins In New Jersey And New York City

(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)