A Texas private prison improperly created a restrictive cellblock to house inmates who were agitating for more rights, according to a Department of Justice inspector general report published Thursday.

The regime in question—known as “J-unit” at the Reeves County Detention Center in Pecos, Texas—was put into place after inmates at the roughly 2,500 strong holding facility for non-US citizens demonstrated against prison guards in early October 2013.

Prisoners had refused to leave their cells in a protest against a lack of “full respect from the officers,” adequate pay for facility work, and permission to move more freely during recreation hours.

Officials claimed that the agitation was spearheaded by Mexican nationals attempting to exert drug cartel influence to pressure fellow detainees into joining their movement. In response, GEO Group removed 364 “suspected leaders, instigators, or participants” from the regular population and placed them in a Special House Unit (SHU).

In many of the cases, the Justice Department found that GEO managers did this in violation of Bureau of Prison rules, by further tightening the screws on inmates without proper oversight. According to Bureau of Prisons regulations, facilities must establish specific policies and procedures before restricting what little rights inmates have. Before creating spaces like J-unit, prisons must tender evidence to justify the structural change, offer inmates placed in the cellblock due process to challenge their new status, and establish other procedures to ensure measures of equal treatment between prisoners in tighter quarters and the regular prison population. During interviews with J-Unit, the Justice Department Office of Inspector General discovered that GEO group rarely complied with these rules.

“One inmate housed in the J-Unit at the time told us that he had been placed there without any explanation and had since lost privileges to work and attend classes,” the report noted. “Another inmate formerly housed in the J-Unit told us that he had been there approximately 8 months and had also never received an explanation of why he was transferred there.”

Of the ten prisoners interviewed by the OIG, only one inmate’s detention was found to be justified. The rest, the IG reported, were placed in J-Unit without evidence, for “erroneous” reasons, or for “infractions unrelated to the J-Unit’s intended purpose.”

Investigators also found that the GEO Group warden overseeing Reeves repeatedly dismissed concerns about J-Unit just two months after it was established, during a December 2013 meeting with BOP contracting officer.

“It’s not a life sentence once [inmates are placed in the J-Unit]. They have to prove they are not one of the leaders,” the warden reportedly said.

The OIG concluded, however, that the situation for those caught in the J-Unit dragnet was grim, noting inmates “have no means to challenge their placement, prove they were not leaders, instigators, or participants, and return to unrestricted general population.”

GEO Group disputed the inspector general’s finding and its call to restore J-unit prisoners their rights by claiming the space is part of the “general population unit” and thus not subject to any kind of special due process scrutiny.

The company, which operates 58 detention and correctional facilities across the US, raked in $1.52 billion in revenue in 2013. Contracts with the BOP were responsible for 16 percent of the company’s earnings. In 2007, it purchased the right to operate Reeves.