The incredible life of a man who is believed to have been the only black IRA volunteer is to be turned into a movie by an Oscar-winning Hollywood producer.

As a black kid growing up in west Belfast in the 1970s, Tim Brannigan had always felt different and always sensed he had been adopted. But when he turned 19, he finally learned his full back story – he had indeed been adopted, but by his own birth mother, Peggy Brannigan.

Brannigan's story – which is set at the height of The Troubles – is already well-known to readers of his captivating memoir, 'Where Are You Really From?'.

In the book he recalls the exact date he learned about his past from his mother – July 13, 1985, because not only had the family decamped to an uncle's holiday home in County Antrim to escape the Twelfth parades in Belfast, but it was also the day that Irish rocker Bob Geldof's epic Live Aid fundraiser for Ethiopia was taking place.

As it turned out, Brannigan's mother had had a fleeting extra-marital affair with a Ghanaian doctor and went to great lengths to hide the pregnancy from her husband and family.

After giving birth to [Tim] Brannigan in May 1966, she placed him into the care of nuns at a local orphanage.

But, as The Irish News reports, she maintained contact with her son and would even take him to her home for weekend visits with the rest of the Brannigan family.

After almost a year, his mother brought him home for good, but pretended she had adopted him, keeping the true nature of their relationship under wraps from her family – and son for the first 19 years of his life.

Brannigan's extraordinary story is now set to get the Hollywood treatment, after he signed a deal with "Birdman" and "Black Mass" producer, John Lesher.

Brannigan's vivid memories of growing up with four brothers in an IRA safe house – where he still lives today – are likely to feature prominently in the picture.

The Irish Times, reflecting on one of his earliest memories as chronicled in his 2010 memoir, states: "The Troubles were their height, and there was a sense of excitement: you could feel it in the house; something was happening. We were an IRA safe house. There would be whispers, a knock at the door, and six men would go upstairs to an empty bedroom. Mum would tell us, 'Don't be saying anything in the street'.

And recalling IRA training sessions in his book, he adds: "This guy lay on the kitchen floor with his rifle poking out the back door. He fired a couple of shots, and the noise was ferocious in the house. It gave me butterflies. It sickened me."

After graduating with a degree in politics in July 1990 from Liverpool Polytechnic England, Brannigan returned to Belfast and was arrested in October that year – and served a seven-year sentence for possession of IRA guns and explosives.

Working as a journalist following his release, he took a year off to care for his mother up to her death from a brain tumor in 2004.

Three years later he managed to track down his father in Ghana - another key moment in his colorful life which is likely to feature in the upcoming movie.

As he recalled in his book, "We met at a hotel, because he didn't want us to go near the house. It was absolutely amazing. He was an impressive man, striking to look at, wearing a long west African tunic over ordinary trousers and shoes. He'd been working with the UN on finding a cure for malaria. I asked him how he met Mum, and he said that was a very personal question. But you're my father, I thought. There's not a family on the planet that doesn't tell that story."

What is evident throughout Brannigan's memoir is the extraordinary bond he shared with his late mother.

Speaking recently of the film deal, he said: "While it's based on my book and is my story, the key character is my mum, whose actions and bravery, especially on the day I was born, were remarkable."

And when quizzed about who might play him in the picture, he added: "No idea – I just hope they do a decent Belfast accent."