This article is part of “Dealing the Dead,” a series investigating the use of unclaimed bodies for medical research. State regulators have ordered a Texas medical school to immediately halt its practice of liquefying bodies after using them for training and research. In a cease-and-desist letter sent Nov. 1 and obtained by NBC News, the Texas Funeral Service Commission said it discovered during an October inspection that the University of North Texas Health Science Center in Fort Worth had been “unlawfully conducting final dispositions of human remains using alkaline hydrolysis.” Alkaline hydrolysis, also known as water cremation, is heralded as an eco-friendly alternative to traditional cremation. It uses water, chemicals and heat to rapidly break down a body, leaving behind a liquid that can be poured down the drain and a dry, ash-like residue that can be returned to relatives. It’s also illegal in Texas, according to the Funeral Commission. “This practice is not authorized under Texas state law and constitutes a serious violation of the standards governing the lawful disposition of human remains,” the commission said in the letter to Health Science Center President Dr. Sylvia Trent-Adams. In a statement to NBC News, Health Science Center spokesperson Andy North pointed to a section of Texas administrative code that lists alkaline hydrolysis as an option for disposing of bodies after they have been used for medical research. But the Funeral Commission said that code was invalid and superseded by state law, which only allows for human remains to be cremated or buried. (Water cremations are legal in more than 25 other states.) The Funeral Commission threatened to fine the Health Science Center body donation program $5,000 per day and revoke its operating license if it didn’t come into compliance within 14 days. North said the center proactively halted water cremations on Sept. 16. That was the same day that NBC News published an investigation revealing that the Health Science Center had dissected and studied hundreds of unclaimed bodies without the consent of the dead or their families. Many of the bodies were cut up and leased to other schools, medical technology companies and the Army, which used them to train students and doctors. In response to the investigation, the center suspended its body donation program and fired the officials who ran it. The Funeral Commission’s discovery raises new ethical and legal questions about the program’s operations. The Health Science Center’s contracts with Dallas and Tarrant counties — which supplied it with unclaimed bodies — stipulated that human remains were to be cremated when the program was finished with them. And consent forms signed by those donating their bodies or the body of a relative to the center also indicated that “cremated remains” would be returned to survivors — giving no indication that the bodies might instead be dissolved. It’s likely families wouldn’t have detected the difference. The fine white powder produced by alkaline hydrolysis — made by pulverizing bone fragments that are left behind after the rest of the body has been dissolved — resembles ashes. Dallas and Tarrant county officials did not immediately respond to questions about whether they agreed to allow the Health Science Center to liquefy unclaimed bodies. Eli Shupe, a bioethicist at the University of Texas at Arlington who previously criticized the center for dissecting unclaimed bodies, said she was shocked when she learned from a reporter that the program had been doing water cremations. “This is a huge ethical issue,” Shupe said. “It doesn’t seem as if they took the wishes of the families very seriously.” North, the Health Science Center spokesperson, did not answer questions about how long the program had been doing water cremations, whether it used that method for all cases or whether it disclosed that possibility to donors or their families. Budget documents from 2020 indicate the Health Science Center planned to install two alkaline hydrolysis units as part of a broader renovation to keep up with a surge in bodies coming into the program, including unclaimed remains from Dallas and Tarrant counties. Dissolving bodies in-house, instead of paying outside companies to cremate them, was expected to save the center $1 million over five years, the budget documents show. Attempts to legalize water cremation have fallen short in the Texas Legislature in recent years in the face of opposition from religious groups, including the Texas Catholic Conference of Bishops, which has argued that the practice “fails to treat the body with dignity and respect.” Critics were particularly incensed by the image of liquefied bodies being poured into the sewer. Regardless of legality, Shupe said that if the Health Science Center was doing water cremations without asking for permission, it would reveal a disregard for the wishes of the dead and their survivors. “If my Catholic mother had donated her body to this program, and I later learned that this is what had happened to her body, I would be sick,” Shupe said. “I would be devastated. Because it’s not what she would have wanted.” This story first appeared on NBCNews.com. More from NBC News: 5 things to know about NBC News’ investigation into unclaimed bodies used for research in Texas Naming the dead: Hundreds of unclaimed bodies were sent to a Texas medical school Cut up and leased out, the bodies of the poor suffer a final indignity in Texas