Wearing a suit from a past life, Matthew Ng is not heading to the office, but to see his parole officer.

Two weeks ago the Australian-educated merchant banker and business entrepreneur walked out of a Sydney prison and his first words were a warning to anyone doing business in China.

Mr Ng had lost almost everything; his booming travel business, his eldest daughter, and now his wife is gravely ill.

In his first exclusive interview since being released from prison, Mr Ng told Lateline how the successful world he built for himself and his family came crashing down in 2010 when he was arrested in his hometown in China and sentenced to 12-and-a-half years in prison.

Sorry, this video has expired Matthew Ng reveals what life was like inside a Chinese prison

Armed with an MBA from the University of New South Wales, Mr Ng had left a job at the Commonwealth Bank and returned to Guangzhou in the country's south, in 2000.

He was the golden boy making good on an overseas education, wanting to build a travel empire in his motherland.

He started the online travel company ET China and was also in an e-ticketing partnership with Southern China Airlines.

When he purchased a majority stake in an ailing state-owned travel company, GZL, it was seen as another positive move.

"The mayor at the time actually issued a statement and said this is the best deal for the city. I was quite a golden boy in Guangzhou," Mr Ng said.

Well connected to the Communist Party and to Western business, Mr Ng epitomised the Chinese dream of financial success.

In fact, he was so successful that Chinese television made a program about him.

His company sponsored the city's 2009 Asian GT Masters car racing event and Mr Ng was one of its celebrity drivers, his glamorous wife Nikki supporting him in the pit.

Matthew Ng and his wife Nikki Chow. ( www.austchinaalumni.org )

With their three children and Matthew's daughter Isabella from a first marriage, the family lived an exciting, travel-filled life.

By the time he was arrested in 2010, the business he had purchased from the Communist government had tripled in size.

Swiss travel giant Kuoni offered 56 million pounds for ET China, a deal that was announced by the London Stock Exchange.

The end of a life

There had been warning signs that the government wanted this now successful company back.

Two of Mr Ng's employees were detained without charge, prompting one of Mr Ng's friends to urge him to flee the country.

"A friend of mine came to my house at midnight, he told me 'Matthew, leave your phone or any electronic items, let's go for a walk'," he recalls.

"We're walking along the river and he told me 'Leave tomorrow. Go elsewhere. Don't stay in China because they'll go after you now'."

Mr Ng took his friend's advice and spent two months in exile, travelling between Hong Kong, London, Taipei and Malaysia, but a mixture of confidence and faith in the justice system led him back to mainland China.

"I'm too confident. I did nothing wrong. I believed that they would still respect law. I mean, if I'd done nothing wrong they could not do anything to me," he said.

"I was stupid.

"My wife Nikki told me once, had she known what I would be facing, she would never ever have come back."

Once back Guangzhou, Mr Ng met with minority shareholders and told them he would not be giving back the company.

He also warned them that if they did not stop harassing his staff and disrupting the deal, he would expose the saga to the foreign media.

"That was the mistake. That threat was taken very seriously. I was detained five days later in my house," he said.

"I drove my car in the compound. Parked my car. I was swamped by eight guys. They lifted up a badge 'police'.

"I was very calm. I called my wife down. I passed her my briefcase, my phone, my wallet. My daughter came down as well. My daughter Alexandra was about five years old at the time.

"She was very happy to see me again, but she was shocked that I was being taken away.

"That was the last time I saw the apartment. That was the end of my last life basically."

'Pissed off the wrong person'

Matthew Ng appears in Guangdong Provincial High Court in China in March, 2012. ( t.qq.com )

Mr Ng said the Chinese officials had already obtained falsified statements about him. Most of the evidence was in the form of verbal testimonies and much of it was contradictory.

Essentially, he was set-up. In Mr Ng's words, he'd "pissed off" the wrong person: the Communist Party chief in Guangzhou who wanted to regain control of GZL.

The Australian Government had taken notice of the former Sydney student's case.

Then foreign minister Kevin Rudd issued a statement voicing his concern about the arrest and then prime minister Julia Gillard raised the case with the Chinese premier at the time, Wen Jaibao, when she visited Beijing.

Nevertheless, when his case finally went to trial in 2011, Mr Ng knew things did not look good.

He said the Chinese government had already made a decision on his fate.

"The court, the judge. It doesn't matter who he or she is. They are not going to go against what the party tells them. In this case unfortunately, the party, they are filled with corrupt or power hungry people," he said.

Mr Ng was sentenced to jail for fraud and bribery.

"During the court recess I went to the bathroom, my brother-in-law from Malaysia came as well.

"I told him, tell Nikki, divorce me, because I don't know whether I can walk out of there alive."

Locked up with psychopaths

Life in prison in China is a daily struggle to stay alive. Mr Ng shared a cell with between 18 and 24 people.

"Murderers, rapists, robbers. People who have totally different life prospects. People who can kill someone for a small argument, for small things. It can be quite violent," he said.

"I shared a bed with someone else, a guy who is a drug dealer and he snores at night. Also there's one guy who's a psychopath, he stabs people at night with pens.

"Everyday is a struggle to stay alive. You have to be super alert.

"One thing in prison was, you can't show emotion. If you're normal, if you appear to be weak, they will stand over you. You will be dead meat."

After four years in this hell, the work of the Australian Government paid off and Mr Ng became the first Australian to be transferred back home under a prisoner exchange treaty.

And there was another devastating blow to come. Mr Ng learnt that his 14-year-old daughter Isabella had died after struggling with an eating disorder while he was in jail in China.

Matthew Ng's daughter Isabella died in hospital in China. ( Supplied )

"She wrote to me when I was in Chinese jail, she said, 'Dad I read the defence statement made by your lawyers and I believe you're innocent and you'll be home really soon'," he said.

"She's from my first marriage. I had her one month after my mother passed away. So to me, I always regarded her as a gift from my mother."

The news of his daughter's death was almost too much to bear and as well as that, Mr Ng's wife Nikki, now also back in Australia, was gravely ill and in hospital.

He despaired about who would look after his remaining three children and he could not understand why the Australian Government was keeping him locked up.

His lawyer Tom Lennox described Mr Ng as Australia's first Chinese political prisoner.

"The subject of a state-imposed sanction whereby your liberty is denied for circumstances that would not constitute a crime on any reasonable test," he told Lateline earlier this month.

Freedom and vindication

After 18 months of lobbying by Mr Lennox, sections of the Australian media and Mr Ng's friends and family, Justice Minister Michael Keenan granted him parole based on his exceptional family circumstances.

Matthew Ng holds up his certificate of release after being freed from Sydney's Silverwater jail on June 15, 2016. ( ABC: John Stewart )

When he walked out of Sydney's Silverwater prison, Mr Ng was met by a small group of his supporters. It was happy and emotional, they joked about cracking open the champagne and getting drunk, and Mr Ng was overjoyed about seeing his family.

When asked there at the gates of the jail about the risks of doing business in China, he issued a stark warning.

"Don't do it. Don't do it. Because not only will you lose your money, you'll lose your life and your family. And that is what happened to me," he said.

Mr Ng is eternally grateful to Australia's Ambassador to China at the time, Frances Adamson, and the rest of the DFAT team in China who continued to work on his case.

"Without them I'd be lucky if was still alive," he said.

In what Mr Ng calls a "postscript" to his ordeal, many of the Communist Party officials in Guangzhou are now in jail themselves.

"The mayor at the time has now gone to jail for corruption. The police chief who signed my arrest warrant, has gone to jail.

"The provincial head of the party Disciplinary and Inspection Committee has also gone to jail."

Two weeks on from his release, Mr Ng prepares to visit his parole officer. He will never visit his homeland again but he is slightly more realistic about doing business with the world's second-largest economy.

"I'm not saying that we should not do business with China. I want people to understand that there are risks involved," he said.

"Just look at me. I had the connections too, I knew the culture, I speak the language. I spent 11 years there before I lost my freedom."

Watch Matthew Ng's story tonight on Lateline at 9.30pm (AEST) on ABC News 24 and 10.30pm on ABC TV.