The last time I saw Lu Banglie, he was lying in a ditch on the side of the street - placid, numb and lifeless - the spit, snot and urine of about 20 men mixing with his blood, and running all over his body.

I had only met him that day. He was to show me the way to Taishi, the hotspot of the growing rural uprisings in China. It felt like heading into a war. Taishi is under siege, I was warned. The day I arrived a French radio journalist and a Hong Kong print journalist were rumoured to have been beaten somewhere around Taishi.

The Taishi election had also been scheduled for that very day, and news of a hunger strike by one of the two most famous figures in Taishi had just come out.

Mr Lu was a very soft-spoken man, one of those skinny guys who looked like he might start tearing at any moment. Born as a peasant in Baoyuesi village of Bailizhou town in Zhijiang city in Hubei province, he was a people's representative and had been in the village of Taishi since the start of a democratic movement in the area.

That movement, deeply unpopular with the local authorities, has come to be seen as a weather vane for China's tentative steps toward a more representative society. It has led to beatings and mass arrests among its population as well as for observers who ventured into its environs.

Mr Lu was at the forefront of this maelstrom. And yesterday this was where the problem lay. We had hired a taxi. Mr Lu got in the car to put us on the right road. As we got closer, I asked him to get out. He refused. "If you go, I go," he insisted. I told him he would be endangering himself, the driver and maybe us. He was unfazed, not even listening. I repeated for a third time that I wanted him to get out of the car. It didn't work. The translator was annoyed and asked me to leave it. Mr Lu knew the risks better than us, he reasoned. So I dropped it, and it was this appeasement that determined Mr Lu's fate.

We arrived on the outskirts of Taishi, just as the dirt roads start. There were 30 to 50 men - angry, inebriated, bored men. Most looked like thugs. Some wore military camouflage uniform. Some wore blue uniforms with badges on the shoulders, and one guy had a greyish-mauve uniform with a walkie-talkie. Our taxi driver, who we had hired randomly in a neighbouring village, was called out by the thugs. They screamed at him: "What the fuck are you doing here?"

He knew nothing. He came back in and screamed at us. "Fuck all of you, look now you've gotten me into trouble."

We told him to reverse but by that time it was already too late, the car was encircled. "Don't go out!," I screamed, telling everyone to lock their doors. I called a colleague on my mobile, asked him to stay on the phone with me.

The men outside shouted among themselves and those in uniform suddenly left. Those remaining started pushing on the car, screaming at us to get out. They pointed flashlights at us, and when the light hit Mr Lu's face, it was as if a bomb had gone off. They completely lost it. They pulled him out and bashed him to the ground, kicked him, pulverised him, stomped on his head over and over again. The beating was loud, like the crack of a wooden board, and he was unconscious within 30 seconds.

They continued for 10 minutes. The body of this skinny little man turned to putty between the kicking legs of the rancorous men. This was not about teaching a man a lesson, about scaring me, about preventing access to the village; this was about vengeance - retribution for teaching villagers their legal rights, for agitating, for daring to hide.

They slowed down but never stopped. He lay there - his eye out of its socket, his tongue cut, a stream of blood dropping from his mouth, his body limp, twisted. The ligaments in his neck were broken, so his head lay sideways as if connected to the rest of his body by a rubber band.

We were probably in the car another five to eight minutes. The front windows were open and various men were reaching in to unlock my door. I held my hand tight to the lock. They punched me, twisted my wrist, tried everything possible with a quick grab to get me out. But I wouldn't let go, and I defended myself while watching Mr Lu get beaten through the window.

Eventually, my translator got out. I followed. They opened my pen, searched my pockets, underwear and socks, asked my translator if his watch could record anything. They asked what we were doing in Taishi. They found my Chinese press pass. "You foreigners you are ruining Taishi," they screamed. "You write write write so much about what's happened here that all these businesses have fled the new industrial zone."

My head was spinning. I was in a mixed state of shock at what had happened to Mr Lu and utter fear for my life.

I shamelessly begged. I prayed. I offered them money. I tried to smile at them. Random people came up to Mr Lu and kicked him in the head, clearing their nose of snot on his body, spitting on him, peeing on him, showing off for each other. I had no idea what to do.

I stood there, sweating, my hands ripping my hair out, just staring at the blood all over the man who had risked his life to help me.

An ambulance came. The medic got out, checked his pulse and left. Then it hit me: I'd done absolutely nothing to save Mr Lu. I stood there watching. I'm trained as a medic, and I did nothing to save Mr Lu. Absolutely nothing. They put us in a car, told us we were being taken for interrogation. On the way the men joked, laughed and we shook.

Mr Lu spent his adult life working to empower villagers and to get the attention of Beijing and the world. He was beaten up many times, had scars all over his body. This, he thought, was part of his work.

Once at the township, they put us at a conference table with flowers and spring water. About 15 officials sat round it and politely questioned us, videotaping the interaction as if it were a TV show. "Why did you come to Taishi? Why did you meet Lu Banglie? How did you meet him?" they asked.

"We are not interested in the reception of media interviews of any kind at this juncture in time," one official explained.

His superior arrived: Ms Qi Hong, associate director of the government news office in Guangzhou. "China is open to foreigners," she said. "We welcome any journalists in Guangzhou, but if you don't follow the proper procedures how can we guarantee your safety?"

The initiator of Mr Lu's beating sat at the table, eyes bloodshot, arms crossed at an angle, his elbow jutting into the air as if to show his extreme disinterest in us.

They said we had broken the law by coming here without permission. We apologised. That is all, that is how the night ended. We walked out of the government building, still being filmed, across the lawn, past the Chinese flag at high mast, and into the car.

They waved and smiled, filming us as we drove off. And this is all I can say about the story of Mr Lu because I never saw Taishi from the inside and cannot tell you how it looks, what the people say, how the air feels.

What I can tell you is that what's going on in Taishi is perhaps the most significant grassroots social movement China has seen since the Cultural Revolution, a rural revolt against corruption, against deterioration of healthcare, against the illegal sale of farmland, and broadly against urban capitalism that has reaped no benefits for these farmers.

The Guardian has been unable to confirm what happened to Mr Lu.

Police said they had received reports that he had been taken to hospital, but that he had been released and was "fine". The three nearest hospitals said that no one had been admitted yesterday.

The last words of Mr Lu I wrote down were: "The police cover their arses. They employ all these thugs whose lives mean nothing to them to kill you. That's why once we are in this we can't go out."