THE LAST time I saw Stuart Gair alive was in a bar just off George Square in Glasgow. I'd spent the best part of the previous five years campaigning for his release from jail for a crime he didn't commit. He'd just been bailed from prison pending his appeal against a life sentence for murder.

It should have been a celebration, but Stuart was homeless and strung out on drugs. He was pale, thin and had trembling heroin sweats so bad that his shirt front was soaked through. He asked if he could crash at my house for a few days. He'd just been thrown out of the house of another friend and supporter - a prison doctor who had tirelessly campaigned on Stuart's behalf - because he'd been shooting up heroin while the doctor's children were about. I had kids too - two little girls aged under five. So, I had to turn my back on him, although he didn't show any anger or act as if he'd been betrayed.

It took until the summer of 2006 for the appeal court to finally clear Stuart's name of the murder of Peter Smith, a former soldier. Smith was stabbed to death in an alleyway in the city centre of Glasgow often used by rent boys.

I met key witnesses who had identified Stuart as the killer. They admitted to me that they perjured themselves following police intimidation. Prosecution witnesses who had placed Stuart at the scene of the crime told me that police officers had threatened to expose them as gay - the men were in the closet - unless they pointed the finger at Stuart.

I uncovered an alibi for Stuart's whereabouts at the time of the murder. Forensic evidence was proved to be fundamentally flawed. Even the family of Peter Smith told me that they had come to believe that Stuart was innocent. By 1999, I'd laid all that information out before the public in the pages of this newspaper. It took another seven years before the state recognised his innocence.

Just to make life difficult for Stuart and for an irritating reporter like me, the prison system repeatedly denied me the right to interview him while he was still inside. That's until the Sunday Herald threatened to sue, however. Then life became a lot easier. Before that, Stuart and I mostly had to rely on time-consuming letters, all of which I still have. I was reading them the other night. In person, he was diffident and conscious of his lack of formal education. In print, he was more free and confident, a well-read, amusing, intelligent man. If life had dealt him another hand, I'm sure he would have been a writer and a good one, at that.

In the intervening six years since I last saw him, the stories I heard about Stuart had a miserable inevitability to them. He kept getting arrested for heroin possession with intent to supply and drifted about from hostel to hostel, dossing where he could. He even took money from the bank account of his elderly disabled mum and stashed drugs to deal in her nursing home. And there was another tale about him giving booze to kids.

He'd spent 13 years as an innocent man behind bars, he'd got hooked on smack while in prison, and then when the system finally, grudgingly, decided that he might not be a killer after all, it threw him out on to the streets an angry, confused addict, without a penny in his pocket or a roof over his head.

Last Tuesday night, I got a phone call from John McManus, who runs the Miscarriage of Justice Organisation (Mojo) in Glasgow. On the previous Friday, Stuart suffered a minor heart attack. Alone at home in his flat in Leith, Stuart called 999 and waited for the ambulance.

IN a final irony, for a man who lived his life in the media glare, the paramedics who arrived had a camera crew in tow. TV investigative journalist Donal MacIntyre was making a film about the emergency services. Stuart recognised the reporter and started telling him about his life. Not long into the conversation, Stuart's head rocked backwards as he suffered the first of a series of massive cardiac arrests which starved his body of oxygen. By the time the medics got him to hospital, he was effectively brain dead.

Machines kept Stuart alive until Tuesday, when doctors at Edinburgh Royal Infirmary eventually tracked down his friends, McManus and Paddy Hill, one of the Birmingham Six. Hill- who spent 16 years in jail for IRA atrocities that he did not commit - now lives in Beith with his family, but still bears the mental scars of what he went through.

They stayed with Stuart while doctors switched off the machines. Ian Stephen, the acclaimed Scottish psychologist and a prominent member of Mojo, was also there.

On Wednesday, I travelled from Glasgow to Edinburgh with Stuart's friends. John from Mojo was there, along with his colleague Cathy Molloy, and Hill was driving. They needed to go through things at this flat; look for important documents. They needed to do simple things too, like empty his fridge, cancel the phone and gas. They needed to tie up the loose ends of his life.

While we drove from city to city, they told me about the last two years of Stuart's life and how he'd turned the corner. After his final spell in jail for heroin, he'd stayed clean. He'd even managed to kick the horribly-addictive medically-prescribed heroin substitute methadone last Christmas.

This was a man who'd somehow rediscovered his lust for life. He'd got a flat, he was writing, eating well, swimming, hill-walking, chasing women and falling in love. Somewhere, just over the horizon, lay the promise of at least a £1 million pay-out from the state for wrongful conviction. One moment, he was thinking about moving to the country, the next of living the life of a well-heeled urbanite .

The front door of Stuart's flat has multiple locks - a hangover from prison that many victims of miscarriage of justice suffer from; they need the security of the locked door before they can sleep at night. The flat was neat and tidy, smelling faintly of soap and aftershave.

By his bed-side was a little bag with a tiny amount of hash inside. Beside it, was a book on Buddhism, some joss sticks and candles. Cathy started looking for his papers. She and Stuart were close, like a brother and sister, and he'd told her his entire life could be found in a little brown washbag. Cathy broke down when she found it. Inside, there were pictures of his mum - who is now dead - and his birth certificate with the father's name left blank.

Some CDs by Amy Macdonald, Damien Rice, Johnny Cash, Moby and Joni Mitchell were at his bedside too.

A little while later, Stuart's girlfriend Mairi arrived. She asked for her second name not to be used in any article. She cried in Cathy's arms and then crumpled to the living room floor as John tried to explain what had happened. She'd only found out that her lover had died that morning - a day after his death - when a friend read a small report in the local paper. Mairi had been at her parents' home in Fife, and because of the problems the doctors had finding next of kin, no-one had contacted her.

"I can't bear to think of him all alone in that hospital, dying by himself, when I could have been with him," she said over and over again, in a low, keening voice. She and Cathy hugged again. Then they talked, and Mairi spoke of Stuart's 17-year-old daughter. Everyone in that room thought that she had died years ago as a young child. But apparently, she was alive and well and growing into a young woman somewhere in Scotland.

Who knows why Stuart only spoke of her to Mairi. He was a man who liked secrets. Mojo staff hope they can find her by the end of next week when Stuart will be cremated and his ashes scattered over Arthur's Seat in Edinburgh where he loved to walk with Mairi. He has few other living relatives.

FATE had it in for Stuart Gair. All his roles in life set him up for a sorry end. A little boy who never knew his dad; a teenage petty thief fitted up for murder; a jailbird junkie on a mission to self-destruct; and finally a man on the road to happiness with a misfiring heart in his chest that he knew nothing at all about.

Jim McGregor - the prison doctor who first contacted me to campaign on behalf of Stuart and then had to face what he calls the "horror story" of Stuart taking his drug problems into his home - says the state must accept its part in Stuart's death.

"I half expected one day to hear that Stuart had been found dead," he said. "The only lesson to be learned from his life is that the police and courts are corrupt and nothing has changed. No-one has had the balls to change the system which his case showed to be rotten.

"Everything remains the same, so more innocent people will end up going to prison, and more damaged individuals will end up coming out. And still - to this day - we do not know who killed Peter Smith. A killer is still on the streets. God knows how many others suffered at his hands."