For more than 30 years, China has upheld a strict one-child policy. And despite the country's growing prosperity, novelist Ma Jian discovered that ruthless squads still brutally enforce the law with vast fines – and compulsory sterilisations and abortions

In China, procreation and childbirth are, like every facet of human life, deeply political. Since the Communist party came to power in 1949, it has viewed the country's population as a faceless number that it can increase or decrease as it chooses, not a society of individuals with unique desires and inviolable rights. At first, Mao Zedong encouraged large families and outlawed abortion and the use of contraception, urging women to produce offspring who would boost the workforce and the ranks of the People's Liberation Army. My mother dutifully gave birth to five children. Our neighbour, Mrs Wang, produced 11, and was declared a "Heroine Mother" by the local authorities and given a large red rosette to pin to her lapel.

Mao's reckless strategy caused China's population to double from about 500 million in 1949 to almost a billion three decades later. By the time Deng Xiaoping took over the reins in 1978 after the calamitous cultural revolution, not only was Mao dead, but so was all faith in communist ideology. Deng knew that for the party to regain legitimacy, it would have to achieve economic growth, and a small group of technocrats, headed by rocket scientist Song Jian, persuaded him that for China to meet its economic targets for the year 2000, its population would have to be restricted to 1.2 billion. The one-child policy they proposed was swiftly introduced: couples in China could have only one child, or in the countryside two if the first child was a girl. The production of children became as subject to state targets and quotas as the production of grain and steel.

Although initially introduced as a "temporary measure", more than 30 years later this barbaric experiment in social engineering is, astonishingly, still in force. China's totalitarian government may have relaxed its control of the means of production, but it has maintained firm control of the means of reproduction, and continues to intrude into the most intimate aspects of an individual's life, stunting relationships, destroying traditional family life and spreading fear. Two generations of children have grown up without siblings, uncles, aunts or cousins. Women have lost sovereignty of their bodies. The state owns their ovaries, fallopian tubes and wombs, and has become the silent, malevolent third participant in every act of love.

In the countryside, where children are needed to help out in the fields and provide for parents in old age, and the preference for sons is still strong, the policy has met with particular resistance, and has been enforced, periodically, with ruthless determination.

A tiled mural in Guangzhou promotes China's one-child policy. Photograph: Sutton-Hibbert/Rex Features

In 2007, I read of riots breaking out in Bobai County in China's south-western Guangxi province. Under pressure from higher authorities to meet birth targets, local officials had launched a vicious crackdown on family-planning violators. Squads had rounded up 17,000 women and subjected them to sterilisations and abortions and had extracted 7.8m yuan (£800,000) in fines for "illegal births", ransacking the homes of families who refused to pay. Tens of thousands of peasants occupied Bobai County town and set fire to government buildings to protest against the crackdown. This was the largest outbreak of popular unrest since the 1989 student protests in Tiananmen Square.

Shortly after the Beijing Olympics of 2008, I travelled to Guangxi, where I had decided my new novel, The Dark Road, would open. Before I start work on a book, I often go on a journey. I need to immerse myself in the places I write about: inhale the scents, tread the dusty paths and absorb the rhythms of the local speech. By the time I arrived in Bobai, almost a year after the riots, the burned government buildings had been repaired, but there was still anger in the air. A vast hoarding above the town entrance showed a couple and their single child and the message: "When every family benefits from the family planning service, every village will rejoice and blossom." The road beyond was lined on both sides with brand new family-planning propaganda signs that were the same rectangular shape and blue-and-white colouring as the surrounding traffic signs. The effect was oppressive and surreal.

I spoke with roadside hairdressers, stallholders and hostel room attendants, and asked them what had led to the riots. "Those corrupt officials!" one man said. "They just used the crackdown as an excuse to line their pockets. Have you seen the lavish new office blocks they've built themselves?" A man with a motorbike agreed to take me to meet a family who had been persecuted the previous year. "They live in a remote valley, far from the nearest village, so the local officials are unlikely to see us," he said as I climbed on behind him. He drove me through dark green hills, past brick shacks painted with half-defaced slogans, one of which read: "After the first child: insert an IUD; after the second: sterilise; after the third: kill, kill kill!" When we arrived at the house, Ah-Li was laying out shrivelled, salted vegetables to dry in the sun. She had to care for four children and her husband's elderly parents, and looked much older than her 30 years. When I asked her about the forced abortion she suffered, she flinched. "It crippled me," she said. "I couldn't stand up straight for weeks afterwards. I had to spend hundreds of yuan on painkillers."

"I heard you worked in a factory in the south for a few years, so you must have had some savings. Did the family-planning squad take the lot?" I looked down at her spindly neck and the duck droppings scattered over her concrete yard. The warm air smelled of singed feathers. I could hear shouting coming from the four children and the television inside her small house.

"Yes, the gods are always against me!" she sighed. "I tried to travel to the county town to lodge a complaint, but the police turned me back. If you write about my story on the internet, don't mention my surname." She rose to her feet and brushed the dung from her trousers. "I paid thousand-yuan fines for my second, third and fourth daughters, but the squad told me that those didn't count, and I'd have to pay another 10,000 yuan for each of them."

"Was the aborted baby a girl or a boy?" I asked, feeling uncomfortable questioning a stranger about such matters.

An abortion room in a small country hospital in Sichuan, China. Photograph: Sinopix/Rex Features

"I don't know," she answered. "When the squad turned up, I was cradling my youngest. The officers tore her from my arms, kicked me in the belly and forced me into the minibus. In the clinic, they gave me a shot in the arm. When I woke up two days later, the baby in my belly was gone. I didn't realise until a month afterwards that they'd sterilised me as well. Every woman in this county has been sterilised – apart from the ones who managed to escape. Now look what I've become: a useless, withered wreck." From behind her dark fringe she eyed me with a look of distrust and despair.

On the way back to Bobai town, I asked the driver where the escaped women had fled.

"At the start of the crackdown, many pregnant women went to hide near the reservoir, but the police hunted most of them down and took them off for abortions. The ones who escaped fled to the Yangtze. Very few of them have returned." I packed my bag, then set off for the river.

Two thousand years ago, after Confucius was forced into exile by the Duke of Lu, he roamed through the outlying states and wrote: "If my path comes to an end, I will board a raft and drift towards the sea." In today's China, where every inch of land is controlled by the state, rivers still offer refuge to the nation's outlaws and outcasts. Dressed in scruffy jeans and a frayed shirt, I posed variously as a migrant worker, a tramp, or a traveller in search of adventure, and lived among family-planning fugitives in their dilapidated barges on the Yangtze. Most of the families had three or four daughters born "out of quota". They live abnormal lives on the margins of an even more abnormal society, picking up menial jobs in the river towns, raising ducks, scavenging refuse sites, hoping to produce a longed-for son who will carry on the family name; all the while nervously scanning the banks, ready, at the first sight of a police van or family-planning squad, to pull anchor and set sail.

Along the banks of a Yangtze tributary in Hubei Province, I approached a battered houseboat. The pregnant woman inside glanced up at me like a thief caught red-handed. When I asked if I could hire her boat for a sightseeing trip, she relaxed and said: "No, I need to deliver a cargo of rice to a restaurant downriver this afternoon." We fell into conversation. She told me she'd escaped Bobai with her husband and two daughters, and had been living on the river for almost two years. When I told her I had a three-year-old daughter, she smiled briefly. Then she stroked her large belly and, tears filling her eyes, told me that before she left Bobai she was given a forced abortion. The eight-month-old foetus was a boy. "He was still alive after the nurse pulled him out from me. He was a tough little creature. He clutched the nurse's sleeve and wouldn't let go. She had to peel his fingers off her one by one before she could drop him into the bin." I stared at the woman's gold-plated wedding ring, and the dirt caught beneath her fingernails. She looked at the ducks foraging the rubbish-strewn bank and said: "Not many tourists come here. The water's so polluted. You should go to the Li river near Guilin. It's a world-famous beauty spot."

I travelled by passenger ferries and cargo barges to the southern province of Guangdong. In Chinese philosophy, rivers represent the life-giving yin, the "eternal female". But on my long journey down the poisoned waterways of China, I discovered that the rivers are treated with the same callous disregard as the bodies of Chinese women. In the rivers' lower reaches, death was everywhere. Decaying waste, polystyrene scraps, yellow factory effluent and dead animals seemed to clog every channel. When a black plastic bag floated past, my fellow passengers would point at it and mutter under their breath: "Another dead baby."

A baby is carried in a basket on his mother's back, Beijing. Photograph: Peter Parks

In Guangdong's Fengzhong County, I had my teeth cleaned in an unregistered backstreet clinic that provided services ranging from dentistry to abortion. The doctor's face was caked in thick foundation that creased into fine lines when she smiled. When my painful ordeal was over, I climbed out of the broken chair, spat into the basin and said: "I have friends in London who'd love to adopt a Chinese baby, and here you are aborting them every day …"

"Most of the women who come to me for abortions would carry to term if I found them a rich couple to buy their child," she said, counting the notes I had handed her. "The government orphanages sell baby girls for 40,000 yuan [£4,250], and they're usually undernourished or deformed in some way. I sell healthy newborns for half that price, but not to foreigners – they can only buy from the state."

"I read in the papers a few years ago that the police near here stopped a van, searched the boot and found 28 baby girls tied up in black plastic bags," I said, rubbing my sore gums. "One of them had already suffocated to death. The hospital staff who sold them to the gang were tracked down and executed."

"Those child traffickers have no conscience – they sell babies by the batch," she said. "I sell on a strictly one-to-one basis. I'm performing a good deed, and I only take a small cut. The fine for having a second child has risen to 10,000 yuan [£1,060]. No couple wants to spend that amount of money on having a second girl. When I give the women an ultrasound and they discover it's a girl, I always tell them that, these days, girls and boys are equal. I have one daughter, and she's just given birth to a little girl herself, and we're all perfectly happy."

A few days later, while walking along the banks of the Pearl river, I saw a dead baby lying in an opened black plastic bag. I had seen discarded foetuses in China many times before: purple lumps of flesh lying on rubbish heaps or inside communal dustbins. But this was a pale, fully grown, newborn baby, with the umbilical cord still attached. A passerby had spotted it, and was prodding it with a wooden stick.

Female infanticide and sex-selective abortions are one of the many unintended consequences of the one-child policy. For every 118 boys in China, there are now only 100 girls.

In a small village in remote Guangdong, a contact took me to her local family planning centre, and told the director that I was a state reporter from Beijing. He took me to his office and we talked for hours. Backlit by a dusty window, he leaned over his desk and showed me the record book that meticulously charted the menstrual cycles and pelvic examination results of every woman of childbearing age in the village. He said 98% of the 280 women were fitted with IUDs. Every three months, he broadcasts an announcement through the village summoning every woman for a mandatory ultrasound to check that her IUD is still in place.

"How do you know when a woman is menstruating?" I asked him.

"She has to report her cycles to the family planning monitor assigned to her street," he said, his silhouette now black against the bright window.

"And how do they know she isn't lying?"

"If the monitors suspect anything, they'll rummage through the woman's bins to check for soiled sanitary towels."

"And what if you discover she's fallen pregnant without permission?"

"We set to work on her."

"What do you mean?"

"We persuade her to have an abortion. If she refuses, she must pay a fine – three times her annual salary. A few years ago, the county authorities insisted we meet our targets, so we couldn't let anyone off. We had to round up every woman who was pregnant without permission and bring her here for a termination."

"What if they refused to come?"

"There were four of us – they didn't stand a chance!" He grinned and sucked on his cigarette; then his face dropped, and he fell silent. "My cousin was six months pregnant at the time. I had to drag her here myself and oversee the termination. She won't speak to me, even to this day …"

Before I left, he took me to the adjoining room and showed me the ultrasound machine and the steel table on which abortions are performed. I stared for a while at the stirrups hanging loosely on either side and at the large plastic bucket on the ground. In the far corner of the room was a faded poster proclaiming: "Girls are as good as boys."

Chinese officials recently announced that 336m abortions and 196m sterilisations have been performed under the one-child policy. An abortion or sterilisation performed on a woman against her will is an atrocity that, one might assume, could only happen during temporary periods of social psychosis or war. But the Chinese government has been committing these crimes against humanity systematically, and on a massive scale, for more than three decades, during a period of peace and growing prosperity. The elimination of life and assault on human dignity dictated by the one-child policy belong with the worst tragedies of the past 100 years.

In March, Communist party leaders confirmed that "China will not change its basic state policy on family planning". They continue to assert that the policy has prevented a Malthusian apocalypse and created economic growth. But demographers such as Wang Feng, Yong Cai and Boachang Gu claim it is not only evil, but unnecessary: the birth rate was already in decline before the policy was introduced, and would have continued to decline naturally due to urbanisation and rising incomes. China's problem today is not overpopulation, but a shrinking labour force that now threatens the country's future growth. It is this, rather than any concern for human rights violations, that is prompting sections of the party to consider phasing out the policy. The Chinese dictators will not willingly relinquish total control of reproduction. But if the policy isn't stopped soon, and the violations and massacres committed in its name are not recognised, the consequences will damage the nation for generations to come.