Britain’s Channel 4 News has obtained video said to have been recorded secretly in a military hospital in the Syrian city of Homs, showing patients shackled to their beds and bearing marks consistent with reports of torture at state-run medical facilities.

According to the French photographer who smuggled the video out of Syria, it was provided to him by an employee of the hospital who said he witnessed wounded civilians and rebel fighters being tortured there by medical staff and members of the security forces.

The Channel 4 News video report, which contains distressing images and accounts of gruesome incidents of torture at the hospital, includes an interview with the man who said he recorded the footage. The interview was conducted by a French photographer who uses the pseudonym Mani to report from Syria.

Restrictions on independent reporting inside Syria, imposed by the government, make it impossible to verify the authenticity of the footage, but the photographer who provided it, and conducted the interview with its source, shot remarkably vivid footage of the fighting inside Homs in February that was broadcast by Channel 4 News last month.

In the interview, the Syrian man said: “I have seen detainees being tortured by electrocution, whipping, beating with batons, and by breaking their legs. They twist the feet until the leg breaks.”

He added: “I saw them slamming detainees’ heads against walls. They shackle the patients to beds. They deny them water. Others have their penises tied to stop them from urinating.”

The man also said that doctors in the hospital “perform operations without anesthetics” on detainees. Protesters injured during the crackdown on dissent in Homs were said to be taken to the military hospital for treatment.

One of Britain’s leading forensic pathologists, Derrick Pounder, examined the footage for Channel 4 News and concluded that the marks on one patient’s chest were likely to have been caused by blows from instruments like a whip and an electric cable shown near his bed in the hospital ward.

Jonathan Miller, a Channel 4 News correspondent who was in Syria in November, reported:

When the allegations that state-run hospitals had been turned into torture chambers first began to surface late last year, I was in Damascus. At the Tishreen Military Hospital, just north of the capital, I put the allegations to its director, Gen. Faysal Hassan, who insisted that wounded insurgents and injured civilian protestors are accorded the same level of care as any other patient. “If a terrorist comes injured, we give him every treatment,” the general said. “And armed civilians.” “So what is your reaction to allegations that military doctors are refusing to treat injured protestors and are even doing worse – are involved in acts of torture?” I asked. “This is untrue,” he said. After which, he denied that Syrian army tanks would ever fire into civilian neighborhoods.

Despite Syrian government claims to the contrary, recent satellite images posted on Facebook by the United States Embassy in Damascus on Monday offered more evidence that forces loyal to President Bashar al-Assad did launch a sustained military assault on the Homs neighborhood of Baba Amr last month. One of the declassified satellite images showed artillery pieces firing into the city on Feb. 25, and smoke and fire from the impact of the shells.

In an explanation of the composite image, Ambassador Robert Ford wrote that it “clearly shows the Syrian army’s equipment ringing the city of Homs. I want to be clear to those bloggers who said that this firing position is a normal military base with the artillery deployed normally. We know that these guns are aimed at Homs and that they are firing at Homs. Armed opposition groups do not have artillery.”

Other images, showing a school and a medical clinic on Feb. 5, at the start of the offensive, and again on Feb. 29, offered stark testimony to the damage caused to Baba Amr by three weeks of sustained bombardment.