A federal judge in Arizona has slapped the U.S. Border Patrol with sanctions after he found that agents had "negligently" or "willfully" destroyed evidence of alleged inhumane treatment of immigrants in Tucson detention centers.

Videotapes from Tucson sector stations were erased or recorded over in the midst of an ongoing civil rights lawsuit filed against the Border Patrol by a coalition of human rights groups who say agents routinely hold immigrants in cold, dirty, and inhumane cells. The suit (pdf) was filed in June on behalf of three plaintiffs who said detainees are denied food, water, and medical treatment, and held for extended periods of time in facilities which the Border Patrol claims are designed for short term detention.

Judge David C. Bury, who issued the sanctions Monday, in August had ordered the Border Patrol not to destroy footage of detainee holding areas—but agents did not comply.

"The Court concludes the destruction of the video-tape recordings made prior to this Court's August 14, 2015, Order was, at best, negligent and was certainly willful. Defendants provide no explanation why, in response to Plaintiffs' notifications regarding litigation, the Defendants did not undertake the efforts initiated in response to the Court's August 14 Order," Bury wrote.

Agents will now have to produce all remaining videos from the past several months within two weeks.

James Lyall, an attorney with the ACLU, one of the groups which filed the lawsuit, told the Associated Press that a judge issuing sanctions against a government agency is a rare move.

"We believe the destroyed video would have shown the Border Patrol failing to follow its policies and subjecting countless individuals, including our clients, to inhumane and unconstitutional conditions. So the court was right to impose sanctions for the agency's deliberate destruction of key evidence," Lyall said.

The Border Patrol's Tucson sector covers 262 miles of the U.S.-Mexico border. According to the suit, it is one of the most heavily enforced regions. The detention centers are known colloquially as "iceboxes" for their intentionally low temperatures. The lawsuit states:

During their confinement, Plaintiffs and many others like them—men, women, and children—have been subjected to inhumane and punitive conditions.  They have been packed into overcrowded and filthy holding cells with the lights glaring day and night; stripped of outer layers of clothing and forced to  suffer in brutally cold temperatures; deprived of beds, bedding, and sleep; denied adequate food, water, medicine and medical care, and basic sanitation and hygiene items such as soap, sufficient toilet paper, sanitary napkins, diapers, and showers; and held incommunicado in these conditions for days.

Named in the suit are facilities throughout the state, including Bisbee, Casa Grande, Douglas, Nogales, Tucson, and other cities.

"There is no justification for these savage policies," Lyall wrote in a blog post in June. "The systemic mistreatment of individuals in Border Patrol custody is both cruel and unconstitutional. We hope that this lawsuit will be the first step to holding Border Patrol accountable for this cruelty and abuse."