There have been many bizarre revelations about the way Guantanamo Bay detainees are treated by their captors. The latest involves the deadliness of olive oil.

For years, nurses at Gitmo have offered hunger-striking detainees a choice of lubricants for their nasal passages while they're being force-fed a liquid nutritional supplement. The lubricant is meant to aid the progress of a tube shoved into their nostrils and snaked down to their stomachs — a painful process that has been widely condemned by medical ethicists and human rights groups.

"We will use olive oil or some type of lubricant,” a medical officer told VICE News last December, during a tour of the detention hospital. “It seems that the detainees prefer the olive oil. We want to make sure we keep them as healthy as possible.”

But last week, olive oil was abruptly removed from the list of lubricants nurses use to grease up nostrils. That's because the military found out inhaling fatty oils irritates the lungs and causes a serious illness called lipoid pneumonia. The disclosure undercuts the military’s assertion that it provides exemplary medical care to Guantanamo detainees.

It also comes on the heels of an extraordinary development this week involving a Navy nurse at Gitmo who refused to perform force-feedings. He claimed, according to a verbal account a detainee gave his lawyer, that the procedure constituted a “criminal act.”

“This is the first time that this has taken place here in Guantanamo,” the detainee told his attorney, according to notes of their conversation she provided to VICE News. “There is a nurse… [who] is the first nurse in the history of Guantanamo who refused to insert a tube on a hunger-striker as a result of observing the suffering that the detainees are going through.”

Colonel Gregg Julian, a spokesman for United States Southern Command (SOUTHCOM), which has oversight of the joint task force that operates Guantanamo, confirmed that the nurse’s protest marks the first time a medical professional has declined to force-feed a detainee.

'The decision to use olive oil is a remarkable instance of negligent medical care in reckless disregard of standard medical practice which was defined to minimize risks.'

Although documented cases of lipoid pneumonia are rare, a civilian doctor is now calling on Guantanamo officials to perform medical tests on every detainee who has been force-fed using olive oil to determine if they're suffering from the condition.

“The decision to use olive oil is a remarkable instance of negligent medical care in reckless disregard of standard medical practice which was defined to minimize risks,” wrote Dr. Steven Miles, an internist and professor of medicine at the University of Minnesota. He was writing a scathing declaration submitted on June 20 in the cases of Syrian national Abu Wa’el Dhiab and Yemeni Imad Abdullah Hassan, Guantanamo detainees challenging the legality of the detention facility’s force-feeding protocols. “The fact that olive oil is listed… as a routinely used lubricant suggests that other prisoners, including [Hassan and Dhiab], have been placed at risk of lipoid pneumonia.”

Miles, who reviewed Hassan’s medical records, said lipoid pneumonia causes respiratory distress that cannot be treated with antibiotics and can result in markings on an x-ray that can “either mimic or conceal cancer, tuberculosis, or pneumonia."

"All the literature on the procedure of inserting nasogastric tubes say that lubrication should be done with a water soluble solution," he said. "Olive oil… is not water soluble."

Three weeks after Miles submitted his declaration, Justice Department attorney Andrew Warden sent an email July 9 to Dhiab’s attorney, Jon Eisenberg. “The detainees who are receiving enteral feeding have been notified that olive oil is no longer available as a lubricant,” Warden wrote. “These detainees are currently given a choice of the following lubricants: water, a water-based lubricant jelly, or viscous lidocaine.”

Although Warden did not say in his email whether the change to Guantanamo’s “long-term non-religious fasts” procedure was made in response to Miles’s declaration, a Guantanamo spokesman confirmed for VICE News that Hassan and Dhiab's hunger strike lawsuit was the reason the modification was made.

"Ongoing habeas litigation challenged [Joint Task Force-Guantanamo's] use of non water-soluble lubricants during enteral feeding," Navy Captain Tom Gresback explained. "Upon review, [Guantanamo's] Joint Medical Group modified its procedures, changing protocol to use only water-based lubricant. This change was implemented to eliminate risk, albeit minimal, for olive oil to get into the bronchial tree and lungs, thereby possibly causing illness,".

Gresback added that water-based lubricants, the "standard of care" in the US, will be the only lubricants used during force-feedings.

“This is an admission that they were doing something wrong,” Eisenberg told VICE News, noting that Hassan’s medical records showed that he has suffered from respiratory distress, though it's unclear if it's due to lipoid pneumonia. “This is medical malpractice on a large scale over a period of many years."

In September 2012, a Yemeni detainee named Adnan Latif who was diagnosed with severe mental health ailments was found dead in his cell. The military said he committed suicide by overdosing on drugs he hoarded. But an autopsy report also concluded that Latif, a frequent hunger striker who was force-fed, had “acute pneumonia” that was a “contributing factor” in his death.

This is not the first time Eisenberg and his legal team have forced Guantanamo to change its medical protocols concerning force feeding, which had recommended the use of a controversial drug to speed up the digestive process and remove the urge to vomit during force-feeding.

The drug, Reglan, is known to cause serious neurological disorders, including one that mimics Parkinson's disease. Medical studies have determined that Reglan is also linked to a high rate of tardive dyskinesia, a potentially irreversible and disfiguring disorder characterized by involuntary movements of the face, tongue, or extremities. The studies prompted the FDA in February 2009 to slap Reglan with a black box label — the agency's strongest warning — to inform patients about the dangers associated with chronic use.

After Eisenberg and Reprieve raised questions and issued their own warnings about the use of Reglan, the drug was removed from a list of recommended medications in the most recent version of Guantanamo’s force-feeding protocols.

When all is said and done, the lengthy and public legal battle that Eisenberg and his colleagues at Reprieve have waged over the past year on behalf of Dhiab — part of a larger battle over his 12-year-long detention — may soon come to an end and render his case moot. The New York Times reported Wednesday that Secretary of Defense Chuck Hagel secretly notified Congress, as required by law, that the military intends to transfer six low-value detainees to Uruguay, possibly next month. Dhiab is on that list.

“The government would surely argue Dhiab is moot,” Eisenberg told VICE News, without confirming or denying whether Dhiab is slated for transfer to Uruguay. “[But] even if Dhiab goes away, the force-feeding litigation doesn’t."