On the move: (clockwise from top left) The book cover of Shantaram; Chowpatty beach in Mumbai; Roberts being extradited from Germany to Australia in the early Nineties; publisher’s blurb for the book; Gregory David Roberts

When you live in a junkie’s hell called heroin, rob enough banks to become your country’s most wanted outlaw, and finally, as a fugitive take to gun-running and hobnobbing with hitmen in a foreign land, in this case India, chances are you may not live to tell the tale. But Gregory David Roberts has not only managed to survive the anarchy of a life lived on the margins but also hammered out a best-selling book from its most galloping, gut-wrenching moments.

It’s an incredible life. And it has resulted in an incredible novel, based on Roberts’s own experiences — a fact that has helped the book stay on popularity charts since its publication in Australia last year. “I took substantive events of my life ... and shoved them around into a story which I hope reads like fiction and feels like facts,” Roberts, 52, said in a radio interview. The book is set to be launched in India in the first week of June.

Titled Shantaram, the novel is woven around the Australian’s flushed and chaotic 10-year-life as a runaway in Eighties’ Mumbai. Once a university student with Leftist leanings, Roberts became a bank robber and was sentenced for 19 years before escaping from Melbourne’s maximum security Pentridge prison.

He came to India on a forged passport, called himself a New Zealander named Lindsay and evolved into the Hindi-and-Marathi-speaking Lin Baba for the slum-dwellers near Cuffe Parade with whom he lived for some time and for whom he set up a free medical clinic.

He left Mumbai after 10 years, was caught in Germany and extradited to Australia. Having served his prison term, he is now promoting his book in England.

In Mumbai, Roberts lived on the knife’s edge. Helping dozens of Afghan and Iranian refugees reach their promised land by forging passports, being picked up by the police and getting brutally tortured in Mumbai’s Arthur Road prison and smuggling guns, gold, explosives and medicines to Afghanistan mujahideens — he did everything he shouldn’t have.

That’s not all. He also enacted sneeze-and-it’s-gone parts in inane Bollywood films like Paanch Paapi and got a new name from village women in a north Maharashtra hamlet where he stayed for five months: Shantaram.

Sifting facts from fiction isn’t easy, especially in a book where reality and creative imagination are like Siamese twins. Especially since Roberts couldn’t respond to The Telegraph questionnaire despite several e-mails.

But nobody could have described the Colaba police station of the Eighties in such morbid, miniature detail without actually being there.

When writing about the corridors, “where shit and piss flowed onto the floor in a repulsive, reeking sludge, men fought each other for an inch of space that was slightly shallower than the muck,” Roberts remembers that the first of the four big cell rooms was known as pandrah kumar or the ‘15 princes’, “where those rich enough to pay the cops to beat up anyone who tried to squeeze in without an invitation” were kept.

The second room had 25 men; the abode known as chor mahal. The third was chalis mahal and the fourth known in lock-up slang as the “black and foetid” dukh mahal, where at least 50-60 men were packed. The humour is dark.

Roberts was in this lock-up for three weeks and spent another three months in the stern Arthur Road jail. There he was chained and tortured twice and “lost 45 kilograms of weight in four months,” though prison authorities are unable to place him now. When beaten up the first time he had fantasies of anger and revenge.

“The second time I was tortured, it seemed to me that I rose above my torn and bloody body; above the men who swung the razor-sharp bamboo canes. It seemed that I understood them. Cruelty, I suddenly saw, even my own acts of cruelty, begins an agony in the self, before it’s inflicted on others,” he wrote in Sydney Morning Herald.

And there in “the flinch and the bite of the chain” where his life hung by the thinnest of threads, Roberts found his zen moment. He decided to forgive. “I knew, somehow, that if I didn’t forgive them, and let the angered injustice go, it would be my soul that they tortured, and not just my body.”

So, he decided to live and later leave India. Captured in Germany in the early Nineties and extradited Down Under, He started writing the first draft of Shantaram while serving his prison term. Roberts had penned about 350 pages in two and half years of work when “a very unhappy prison officer” decided to make him “unhappy”. The officer tore the manuscript into pieces. “He was probably the harshest critic I have ever had,” he joked later.

Roberts then spent another three years writing another 350 pages before another prison guard tore up the draft a second time. “I sat in bed and I was very close to that red vision rage when you just lose control. And I thought, if I do lose control, it will not be just the writing but also the writer who will be destroyed. And, so long as the writer is alive, he can keep working. So I found out the prison officer who did it. I went to him and said, ‘I know you are the one who did it and I forgive you.’”

For a man who had spent much of his adult life fighting, who was stabbed and had stabbed others in return and who knows enough about the art and science of a knife fight to describe it in about 1,000 words in the novel, this was another life-changing nanosecond. He had discovered self-control and a guiltless way of living, something which began in the village that christened him Shantaram.

It wasn’t always like that. In his youth, Roberts was the slave of his instincts. Coming from a family of Fabian Socialists, he grew up in a rough, working-class Melbourne neighbourhood and left school early to marry the girl he loved on his 18th birthday. He went to night school, worked in factories and studied philosophy in Melbourne University. Then his marriage broke up and he lost custody of his daughter. “I was too young, too immature to handle the problem. I fell apart,” he later said.

A friend told him one night that he had the solution and gave him a heroin hit. Roberts was hooked. To feed his habit, he first took to petty thievery, then started robbing banks. He wore a three-piece suit, carried an imitation pistol and said, “Good morning” and “Good afternoon” before doing what he had to. He became infamous as the Gentleman Bandit.

Looking back, some of these robberies had the bumbling humour of a Keystone Kops movie. After his first heist at a cinema, he ran straight into two policemen on the street. The money fell out of the bag on the ground.

“The cops kept looking at the bag and at me,” he recalled in the radio interview. Acting cool, he told the cops that he had just closed his business and was off to a wedding. The policemen bent down, scooped the money back into the bag and handed it back to him. “I said, thank you very much and went off down the road.”

Many robberies later, he was caught and sentenced to Melbourne’s Pentbridge prison. But he escaped and fled to India. He might as well have gone to another planet. India changed him. Through his fictional alter-ego Lindsay’s delinquent existence in Mumbai, the book Shantaram maps this change. The protagonist gets involved at every social level: from the lesser men in the chawls who get drunk and beat their wives to the smooth-talking film producers eager to bed aspiring starlets.

Roberts handles all that with élan. What transforms him is the trust of a small village where he got the name, Shantaram — man of peace. Before the innocence of simplicity, the violent man stands shallow and stripped.

In the end, he surrenders his soul. “These people in this little village in India saw in me something that even I didn’t know was there,” he recalled.

Over 900 pages, Shantaram is the sort of book one must carry with care. Much like the author’s life, it’s a messy novel that occasionally strays for the worse. Sometimes the narrative sags and some characters appear to be caricatures.

Shantaram is as close as fiction gets to reality TV. Fewer books have travelled so deep into the seamy underbelly of Mumbai. Roberts describes Bombay of the Eighties with the exactness of the dabbawallahs he writes about.

But more importantly, he understands the city, its fine lines and its complex soul. You can see that clearly when he talks about the city’s lower middle-class love “where a man didn’t bring flowers or chocolates to the woman he loved but stories from the wider world, where men grappled with demons of desire, and monstrous injustice.”

Rock singer Neil Young once wrote, “Every junkie’s like a setting sun.” Some like Gregory David Roberts also touch the stars.