Media playback is unsupported on your device Media caption Paul Wood and cameraman Fred Scott have been talking to Abu Sakar

It sounded like the most far-fetched propaganda claim - a Syrian rebel commander who cut out the heart of a fallen enemy soldier, and ate it before a cheering crowd of his men.

The story turned out to be true in its most important aspect - a ritual demonstration of cannibalism - though when I met the commander, Abu Sakkar, in Syria last week, he seemed hazy on the details.

"I really don't remember," he says, when I ask if it was the man's heart, as reported at the time, or liver, or a piece of lung, as a doctor who saw the video said. He goes on: "I didn't bite into it. I just held it for show."

The video says otherwise. It is one of the most gruesome to emerge from Syria's civil war. In it, Abu Sakkar stands over an enemy corpse, slicing into the flesh.

"It looks like you're carving him a Valentine's heart," says one of his men, raucously. Abu Sakkar picks up a bloody handful of something and declares: "We will eat your hearts and your livers you soldiers of Bashar the dog."

Then he brings his hand up to his mouth and his lips close around whatever he is holding. At the time the video was released, in May, we rang him and he confirmed to us that he had indeed taken a ritual bite (of a piece of lung, he said).

Now, meeting him face-to-face, he seems a bit more circumspect, though his anger builds when I ask why he carried out this depraved act.

"I didn't want to do this. I had to," he tells me. "We have to terrify the enemy, humiliate them, just as they do to us. Now, they won't dare be wherever Abu Sakkar is."

He is 27, a stocky, tough-looking Bedouin from the Baba Amr district of Homs, with a wild stare and skin burned a dark brown by the sun. He tells me the story of his involvement in the revolution, leading to his current notoriety.

Image caption Abu Sakkar fought with the Farouq Brigade before starting his own

Before the uprising, he was working as a labourer in Baba Amr. He joined the demonstrations when they started in the spring of 2011. Then, he says, a woman and child were shot dead at a protest. His brother went to help. He, too, was shot and killed.

Media playback is unsupported on your device Media caption Watch Paul Wood's interview with Abu Sakkar in full

In a YouTube video from June 2011, Abu Sakkar can be seen at the front of a crowd waving olive branches to greet deserting army officers. He took up arms against the regime, one of the first to join a new organisation called the Free Syrian Army (FSA).

In February 2012, he was fighting with the Farouq Brigade, and they tried, and failed, to stop the regime taking Baba Amr. When the FSA fled Baba Amr, he started his own brigade, the Omar al-Farouq. They saw bitter fighting in Qusayr.

Along the way, he lost another brother, many relatives, and countless of his men. His parents were arrested and he says the police rang him so he could hear them being beaten.

"Put yourself in my shoes," he says. "They took your father and mother and insulted them. They slaughtered your brothers, they murdered your uncle and aunt. All this happened to me. They slaughtered my neighbours."

He goes on to talk about the man whose flesh he held in his hands: "This guy had videos on his mobile. It showed him raping a mother and her two daughters. He stripped them while they begged him to stop in the name of God. Finally he slaughtered them with a knife... What would you have done?"

"If we don't get help, a no-fly zone, heavy weapons, we will do worse - you've seen nothing yet Abu Sakkar

Well, perhaps not make a meal of my enemy, I think. At the time, Abu Sakkar's men greeted what he did with cries of "God is Great". Now the fighters looking after him while he recovers from an injury just seem a bit embarrassed.

Abu Sakkar says the dead soldier was an Alawite or Shiite militiaman. "He was insulting us. He was shouting, 'Oh Ali, Oh Hussein, Oh Haydar [Shia slogans],'" he says.

"In the beginning, when we captured an Alawite fighter, we would feed him, make him feel comfortable. We used to tell him we were brothers. But then they started raping our women, slaughtering children with knives."

A man in the room interrupts to say the Alawites are not proper Muslims. This war is becoming increasingly sectarian.

Abu Sakkar shows me scars from 14 different bullet wounds on his body. "We're under siege, it's been two years now," he says. "Videos from the Shabiha [government militia] show many more terrible things than what I did. You weren't too bothered. There wasn't much of a media fanfare. You didn't care. You suffer a fraction of what we suffered and you'll do what I did and more."

Image caption Abu Sakkar's home district of Baba Amr has seen heavy fighting

He continues: "Qusayr was destroyed, Baba Amr destroyed, Homs was entirely destroyed. No-one cares. See how the refugees are living? Would you accept your parents living the same way? The Syrian people refuse to be humiliated. We are defending the Islamic nation and this is how the Arabs and the West treat us? What did the West do? Nothing."

Is the West asking me now to fight Abu Sakkar and force him out of the revolution? Gen Salim Idris, FSA chief of staff

Finally, he adds: "If we don't get help, a no-fly zone, heavy weapons, we will do worse [than I did]. You've seen nothing yet."

So Abu Sakkar has become the "cannibal rebel" - a handy symbol for all those who, like the Russian President, Vladimir Putin, oppose arming the Syrian rebels.

Standing next to an uncomfortable looking David Cameron, Mr Putin told a G8 summit news conference: "These are people who don't just kill their enemies, they open up their bodies, and eat their intestines in front of the public and the cameras. Are these the people you want to… supply with weapons?"

It is possible that Abu Sakkar was mentally disturbed all along. Or perhaps the war made him this way. War damages men - and Syria is no different. As the poet W H Auden wrote: "Those to whom evil is done, do evil in return."

Image caption Gen Salim Idris: Why do our friends in the West focus on this?

I asked the Free Syrian Army's chief of staff, Gen Salim Idris, why Abu Sakkar hadn't been arrested. His answer tells you a lot about the reality of how the war is being fought on the rebel side.

"We condemn what he did," said the general. "But why do our friends in the West focus on this when thousands are dying? We are a revolution not a structured army. If we were, we would have expelled Abu Sakkar. But he commands his own battalion, which he raised with his own money. Is the West asking me now to fight Abu Sakkar and force him out of the revolution? I beg for some understanding here."

Abu Sakkar seems unsure how to respond to his notoriety. He is, by turns, sheepish, nervous, angry and bitter. He definitely has the look of a man who has seen too many bad things. At the end of our interview he says he is an "angel of death" coming to cash in the souls of the enemy.

After the video became public, his men filmed him making a statement. (Not for nothing has this been called the YouTube war.) In this video, Abu Sakkar is in a freshly pressed uniform, jauntily smoking a cigarette in a way that lends a slightly absurd air to the whole performance. He says he's willing to stand trial - but only if President Bashar Assad does too.

There's no immediate prospect of either men facing their accusers. Nor of peace talks, or even of a ceasefire. And so Syria's descent into madness continues.

Elswhere on the web

The Independent's Kim Sengupta, who has spent time with the al-Farouq brigade in Syria, says Sakkar was once seen as a moderate and "something of a hero". "What made someone who had once cautioned against blaming the Alawites - the minority community from which the ruling elite are drawn - for the regime's actions into their virulent hater?" Sengupta asks. "There is little doubt that brutality with which the regime responded to peaceful protests in Baba Amr and elsewhere in Syria was the catalyst for the armed uprising which followed. But surely that does not explain such levels of viciousness from both sides?"

For others, the release of the video - and its distribution by pro-government websites - was an escalation of a propaganda war between the rebels and Syrian authorities.

"Up until now (in the eyes of most of the international community) it was pretty much a given of which side is right and which side of wrong," writes Newstiller. "The information war pretty much decided that early on when rebels, building on experiences during the Arab Spring, used the internet to gain a strong moral upper hand on Assad's crimes. Today that upper hand looks a little limp. Assad and Sakkar may not want us to think so, but the reality is that there are no good guys in this war."

Peter Bouckaert from Human Rights Watch stresses that Abu Sakkar is "just one man, and there are many other armed fighters in Syria who reject such sectarian actions and would be horrified by the mutilation and desecration of a corpse - let alone an act of cannibalism". He goes on: "Action by the [UN] Security Council would send a powerful message to all sides of the Syrian conflict that abuses such as those committed by Abu Sakkar - as well as those committed in even greater numbers by the Syrian government - will ultimately be prosecuted as war crimes and crimes against humanity."

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