At the mention of a steamed bun, the banned author covers his face before saying: 'I don't really want to talk about it.' Tears trickle out from under Xie Chaoping's hands and down his ruddy cheeks. After 20 seconds, the 55-year-old takes a deep breath and says: 'As a man, I shouldn't cry like this. But I cannot help it whenever thinking about the cold bun. I felt I was weak.' Out of detention after 30 days for publishing a self-funded book, Great Migration, that disclosed the predicament of migrants and the corruption of officials during relocations to make way for the Sanmen Gorge dam in the 1950s, Xie sits on a sofa in his newly rented flat in west Beijing, trousers flapping loosely 'like a skirt', he jokes. He is at least 5kg lighter. One evening during his five consecutive days of five to seven hours of interrogation in Linwei police station in Weinan , Shaanxi province, he returned to his cell after 7pm, too late for dinner. A 17-year-old suspected thief crawled over to him and said: 'Uncle Xie, haven't you eaten? We were given two steamed buns for dinner and I kept one for you.' Xie took the cold bun, stood up, turned and looked at the wall. One bite and his emotions exploded. His wife, Li Qiong , says he has broken down at least 20 times since his release on bail on September 17. 'I have been crying a lot over the bun and my wife,' Xie says. But while he might crack over a bun, Xie says he gave as good as he got after being detained on August 19 and never cried or backed down in front of a rotating team of expert police interrogators. They tried to get him to reveal where the books had been printed, the ins and outs of the publishing process and, critically, how he expected to profit from writing and publishing Great Migration. 'It's political persecution,' he says. 'Those 30 days were like a competition with law enforcers as an old public prosecutor, and a fight with corrupt officials as a journalist. I am confident to say that I didn't lose any face for those two identities. There were a few nerve-breaking, long interrogations. I had to stay 100 per cent focused to defend myself, despite having done no wrong.' Xie's book outlines how peasants were tricked in the 1950s into leaving their fertile land on the promise of a better life in Ningxia . Those who did not starve to death within months were banned from returning to their ancestral homeland until the 1980s. The Weinan migrants have remained on the move for decades, some moving eight times. In 1985 the central government ordered the local government to allocate 20,000 hectares of land to 150,000 migrants and pay them 120 million yuan in compensation. But only about half moved back, Xie's book says. They took up about 70 per cent of the land allocated to them. Xie says that according to Dali county government statistics, their average income in 2007 was about 1,150 yuan - half that of those who were not forced to move. Xie, born in Pingchang county, Sichuan , became a high school history teacher and was then transferred to work in the culture and education bureau. He was later transferred to the procuratorate in Dazhou and began freelancing for legal publications. In 2002, he published a compilation, Evil Family - A Procurator's Diary, of 45 of his anti-corruption articles. He moved to Beijing with his wife in 2005 to work as a journalist for the Procuratorial Daily's Fangyuan Magazine. After spending three years on Great Migration, Xie was turned down by publishers worried about handling the book. Finally, through a friend, Xie found a magazine in Taiyuan , Shanxi , willing to publish it as a supplement. Xie had long suspected his writing would bring him trouble and spent about a year revising his book to ensure no tiny error could be exploited by vengeful authorities. 'I was trying to avoid a civil legal case, but I never expected to be implicated in a criminal investigation.' A few months before he was detained, Xie sensed the toughest part was yet to come when the authorities invited him in for a 'cup of tea'. Xie ended up being charged with conducting 'illegal business' for spending 20,000 to 30,000 yuan of his own money on six trips to Weinan to interview more than 50 people, plus 104,900 yuan to print 20,000 books - more than 15,000 of which were confiscated by Weinan's cultural inspection team in June and July. After Xie's first attempts to publish stories about the embezzlement of flood compensation money were killed by the magazine, under pressure from the propaganda authorities, a group of migrants in their seventies and eighties knelt before him in 2006, 'begging me to record their history - full of tears and blood - to pass on to their descendants', he says. When his interrogators asked him for his impression of the migrants during his trips, he replied that they were poor, bitter and pathetic, while some government officials were too greedy, hateful and corrupt. 'Another reason I was determined to write about this was to disclose the corruption of some officials in Weinan and push the local government to address the issues, returning land and compensation to migrants.' He says each level of government cheated the next level up. Xie quickly found his every move watched in Weinan, while a sinister wall of silence obscured the new ownership of prime farmland. Everybody knows what happened but nobody dares speak out, the locals told him. One seventy-something migrant petitioner, Chen Sizhong , almost deaf and limping, was sent to a labour camp on a charge of subverting state power. 'I don't think they will leave me alone,' Xie says. 'The police asked me at Xian airport on the day I was released if I would co-operate if they continued the investigation. I replied that you can take me back now if you want and I will stay there for as long as it takes.' He rolls up a sleeve and points to a purple-yellow stain on his upper left arm. 'The bruise just faded a few days ago.' His left shoulder was hurt when police grabbed him in his flat. Detained for four nights in Chaoyang police station, Xie was transported to Beijing West railway station with his hands handcuffed behind his back. He bounced around in the van, falling whenever it braked. Police refused to adjust or move the handcuffs over his swollen wrists. Waiting for the train to Weinan, Xie says he was pushed around from one waiting hall to another and handcuffed to a door in front of hundreds of people. 'It was such a huge humiliation to him,' his wife says. Pretending to yawn, a policeman at the station deliberately knocked Xie's raw shoulder. 'It was agony,' he says. 'I couldn't even breathe.' In detention, Xie had to get up at 6am to do hard labour until 11am, and then had interrogations most afternoons. He hurt his back and had to crouch while mopping floors. 'I was in such pain that all my clothes were soaking wet and I knelt down to do my mopping. The warder still shouted 'Stand up mopping!' Drug addicts and thieves were more humane than some of the officers.' Without supportive media and internet users, Xie says he is sure he would have been taken to court. 'I could tell where the whole thing was going as an experienced prosecutor,' he says. 'The interrogators had implied I was going to jail.' After Xie's lawyer, Zhou Ze , visited him in jail, he told media he was surprised to find Xie in reasonably good spirits. 'Actually,' Xie says, 'I was acting to show the warders that I was not easily broken.' Xie plans to write about what happened over those 30 days, even though his diary was stolen by the police before his release. Seven or eight publishers have offered to publish that book.