(CNN) Surveillance video of a transgender immigrant who died in ICE custody may have been deleted while investigations into her death were ongoing, lawyers representing her family said Wednesday. The company that runs the facility says their cameras automatically overwrote the video.

The attorneys said the footage could be key evidence revealing the events leading up to the death of Roxsana Hernandez, a 33-year-old from Honduras who died May 25, 2018, in New Mexico from AIDS complications.

Wednesday, the Transgender Law Center and attorney Andrew Free released an email exchange between officials that indicates surveillance footage was not preserved from inside the Cibola County Correctional Center, a privately run ICE detention facility where Hernandez was held for less than a day before she was hospitalized.

"The requested video is no longer available. The footage is held in memory up to around 90 days. They attempted to locate and was negative," an Albuquerque-based ICE official responds.

They also filed a lawsuit in New Mexico on Wednesday against CoreCivic, the private company that runs the Cibola facility, asking a judge to force the company to release video and other records in the case.

"They were on notice to preserve any and all video surveillance and it seems they may have failed to do so," Free said in a statement. "We filed suit because we have reason to believe they may be withholding more evidence. The public has the right to know what happened to people who die in the custody of the US government and CoreCivic is not above the law."

ICE declined to comment on the video or emails, citing its policy against commenting on pending litigation. ICE has said Hernandez "received all the appropriate medical care possible" during her time in the agency's custody.

CoreCivic said that video footage was not preserved because the company didn't receive notice that Hernandez's family was considering a lawsuit until November.

By that point, spokeswoman Amanda Gilchrist told CNN, "whatever digital images that might have existed had been long overwritten."

Death review reveals details of medical care

The Transgender Law Center also released ICE's "Detainee Death Review" for Hernandez , which the law center said points to "various discrepancies in the medical treatment Roxsana received and immigration enforcement's internal protocols."

One key finding, according to the law center: Hernandez didn't get the HIV medication she needed.

"Roxsana needed medical care and yet she was cleared to be incarcerated. At numerous times throughout her days in immigration enforcement custody, the people she was detained with pleaded for her to receive medical care," Lynly Egyes, the law center's legal director, said in a statement. "It is clear from these records that if immigration enforcement believes that their sole duty is to shuffle people into immigration prisons, that is what they'll do. As a result, the consequences for those who are either sick or who get sick while in their custody can be fatal."

In a statement released by ICE, the deputy medical director for the ICE Health Service Corps said hospitals generally don't begin HIV therapy on a patient who's been diagnosed with significant medical issues.

"The correct selection of an HIV treatment regimen requires a number of laboratory tests to determine which drugs may be most effective for the patient in consultation with a medical provider familiar with HIV care. Hernandez was in transit for most of her brief time with ICE," Capt. Philip Farabaugh said. "When she arrived at Cibola, such evaluation could not take place in such a short window of time prior to her transfer to the hospital."

ICE has said Hernandez entered the agency's custody on May 13, 2018, after several days in US Customs and Border Protection custody at the San Ysidro Port of Entry near San Diego. She was transferred to Cibola on May 16 and spent less than a day in an intake area of the facility before she was taken to the hospital.

Nine days later, she died at Lovelace Medical Center in Albuquerque.

Gilchrist said in a statement that Hernandez was detained at Cibola for only 12 hours.

"Roxsana Hernandez came to Cibola County Correctional Center in May 2018 gravely ill," Gilchrist said. "When she arrived, she went through the intake process which includes a medical evaluation. The medical team made the determination that she needed to be immediately transported to an outside hospital."

Lawyers for Hernandez's family earlier alleged she was physically abused while in US custody and died from insufficient medical care -- claims US immigration authorities have disputed. An April 2019 autopsy report indicated her cause of death was multicentric Castleman disease due to acquired immunodeficiency syndrome.

Correction: This story has been updated to more accurately describe where Roxsana Hernandez was held at the Cibola County Correctional Center. Hernandez was held in an intake area of the facility, but not in the transgender unit. She was held for less than a day before she was taken to the hospital in May 2018.