Liao Yiwu clearly recalls the moment when he first stepped into a Chinese jail. He was stripped naked by inmates who then searched his anus with chopsticks -- the beginning of a four-year prison ordeal.

"I only stayed naked in front of everyone six to seven minutes, but I felt I had lost all dignity," the author and poet said about the start of his 1990 imprisonment after the bloody crackdown on Tiananmen pro-democracy protests.

More than two decades on and despite intense police obstruction, the 650-page account of those four years -- a rare depiction of life in a Chinese jail -- has finally come out in France after first being published in Germany and Taiwan.

The book was a long-time in the making and has come at huge personal cost. Faced with the threat of more prison if he had it published abroad, the 54-year-old decided to flee China in 2011, leaving his mother and others behind.

"They were watching my emails and they knew I was in touch with editors in Germany and Taiwan," he said at the launch of "For a song, for a 100 songs" in Paris.

"They said I couldn't publish the book, and if I did, they would put me in prison again, this time for at least 10 years... The German and Taiwan editors got worried about my safety and they pushed back the publication date.

"All in all, they pushed it back three times. The third time, I decided to escape."

Liao has never fully revealed how he managed to flee over the border to Vietnam in 2011 at a time when activists, dissident artists and authors were under intense scrutiny over fears Arab Spring-type protests would spread to China.

"I used the mafia. China is a very corrupt society, so for once corruption was useful for me," he said at this week's launch, refusing to say any more and explaining he would reveal everything in another book.

Liao's self-imposed exile in Germany is the culmination of decades spent on the wrong side of China's ruling, authoritarian Communist Party.

A young poet in the 1980s, he became enraged with how the 1989 Tiananmen protests were being dealt with. His poem "Massacre" about the bloody crackdown sealed his fate, and he was thrown in jail a year later.

There he came face to face with murderers and other criminals on death row, and experienced torture and sexual abuse.

-- 'Fear of being forgotten' --

On his release in 1994, Liao started writing about his ordeal as he scraped by on what he calls the margins of society.

"I was motivated by this fear of being completely forgotten," he said.

"When I was in prison, I lived through hell. But worse than that was to imagine that people wouldn't be aware of what happened."

He wrote feverishly, filling page after page before police came to visit his home and confiscated the long manuscript. After a month of despair, Liao started all over again.

"I did this with a feeling of terror and urgency. I also realised I had forgotten a lot of details... It took me around two years, and I realised there was a third less than the first version," he said.

Once more though, police came to visit and confiscated his second manuscript. So he started again, but this time he had his work saved on a computer and hid copies in different places.

During that time, Liao also published other books including "The Corpse Walker", which tells the stories of people on the margins of society such as a grave robber or a leper. These were banned in China but were still widely read.

A friend of jailed Nobel Peace Prize laureate Liu Xiaobo, Liao is a keen critic of China's rulers and elite, whom he has accused of accumulating "dirty wealth."

He says he has little hope that human rights in the country will improve under Xi Jinping, who was appointed new head of the Communist Party in the autumn and is expected to be anointed President later this year.

He is also pessimistic about a recently-announced pledge to reform China's long-criticised "re-education" system, in which people can be sentenced to up to four years of labour by a police panel.

"The issue is not one little reform after another, the issue is ending dictatorship because dictatorship is very creative -- if it abolishes one system, it will invent another," he said.

In the meantime, Liao plans to continue writing -- and adjusting to life as a dissident author in exile.

French plainclothes policemen lurked outside the famous Paris cafe where he held the book's press launch -- mild security compared to what he experienced on a recent trip to Mexico.

"I had just got off the plane and the head of police and culture minister were there to greet me. There were lots of police cars and I really thought I was a criminal," he recalls.

"During my stay, there were seven policemen with me at all times, carrying huge guns... Life in exile constantly brings new surprises."