In 1998, Radhika Coomaraswamy, the UN Special Rapporteur on Violence Against Women, was set to investigate reports of sexual misconduct against female inmates in Michigan prisons when Governor John Engler barred her the day before the visit.
In another instance, the late Senator Jesse Helms, formerly of the Senate Foreign Relations Committee, blocked a proposed prison visit by Bacre Waly Ndiaye, head of the UN Human Rights Office in New York, who was planning to observe living conditions in some US prisons.
Now, UN officials, inspired by President Barack Obama's recent visit to the El Reno Correctional Facility in Oklahoma, are once again attempting to gain access to US penitentiaries.
The UN Special Rapporteur on torture, Juan E. Méndez, and the Chairperson of the Working Group on Arbitrary Detention, Seong-Phil Hong, have jointly called on the US government to facilitate their requests for an official visit to US prisons to advance criminal justice reform, Inter Press Service reported.
Méndez has provided the US State Department with a list of prisons he wants to visit in Louisiana, California, Arizona, Pennsylvania, and New York, as well as the Federal Bureau of Prisons in Washington, IPS reported.
Earlier this week, Méndez said he was looking forward to working with the US Department of Justice on Obama's special study on the need to regulate solitary confinement.
"The practice of prolonged or indefinite solitary confinement inflicts pain and suffering of a psychological nature, which is strictly prohibited by the Convention Against Torture. Reform along such lines will have considerable impact not only in the United States but in many countries around the world," he said.
An estimated 80,000 inmates in US prisons are held in solitary confinement, in most cases for periods of months and years.
The UN Working Group on Arbitrary Detention has already drafted a set of Principles and Guidelines that "will help establish effective mechanisms to ensure judicial oversight over all situations of deprivation of liberty."
The document will be presented for consideration by the Human Rights Council in September.
According to published reports, the US prisons system has been home to corruption, unhealthy living conditions and physical beatings, specifically against minorities, including African-Americans and Latin Americans.
During his visit to Oklahoma, President Obama spoke about the need for prison reform, and specifically highlighted the harms caused by solitary confinement.
"Yet the State Department continues to fail to allow the Special Rapporteur on torture access to US confinement facilities to review their use of solitary confinement. It's as if they missed the President's speech," Antonio M. Ginatta, of the US Program at Human Rights Watch, told IPS.
"In light of the president's speech and his visit to the El Reno prison," he continued "the US Department of State should change course and immediately extend an unrestricted invitation to Special Rapporteur Mendez and the Working Group on Arbitrary Detention."