Federal prosecutors in Brooklyn on Friday opposed a request from Amnesty International to meet with alleged drug trafficker Joaquin “El Chapo” Guzman Loera and assess his prison conditions, telling a judge it was none of the human rights organization’s business.

Guzman, who twice escaped Mexican jails, is being held in the Manhattan federal jail in isolation and under tight security that restricts his contact with family members and others. His lawyers have complained he is suffering, and Amnesty requested a visit last week.

“Allowing Amnesty International to visit…would open the floodgates to requests by scores of other non-governmental organizations interested in visiting the defendant or assessing U.S. prison conditions,” the government said. “Acquiescing to this request would set a perilous precedent.”

U.S. District Judge Brian Cogan has set May 5 for the next court hearing on Guzman.