Susan Boyle has admitted she is still haunted by demons from her troubled childhood in her new autobiography “The Woman I was Born to be”.

The 49-year-old star shot to fame last year when she stepped onto the stage of Britain’s Got Talent and wowed judges with her rendition of “I dreamed a dream” from Les Miserable. Despite missing out in the final stages of the competition the signer went on to sign a lucrative contract with Simon Cowell. She has since sold nine million albums worldwide and achieved global success.

In her new book Susan reveals that because she was starved of oxygen during birth doctors told her parents “She will never come to anything, so don't expect too much of her.”

Her new book also reveals that Susan was severely bullied in her youth. The star admits that she has always been able to find peace in singing.

“My singing silenced the bullies, but better than that it silenced the demons inside me.

"When you've been jeered at, told to shut up, sit still, stop being silly, there's noise constantly rolling around inside your head. When I was singing, it was peaceful.

"It gave me a new identity. Instead of being 'That Susan Boyle - do you remember, she was a bit odd at school?' I became 'Susan Boyle - did you know she can really sing?'"

In her new book published yesterday Boyle recounts one of the many bullying offences that she was subjected to.

"One afternoon, a gang of girls and boys started chasing me. I set off, trying to get a head start, running as fast as I could... thinking that if I could just get to the turning into our estate, I would be safe."

But instead she found herself heading towards wasteland.

"My lungs were burning in my chest and my feet were pounding one in front of the other. It was like one of those nightmares where you're trying to run and your limbs won't move fast enough.

"They caught up with me... I was fighting for my life. They grabbed my bag and swung me round so I toppled down the bank towards the stream, landing on my face in a patch of nettles.

"The ringleader, whose name I won't mention, stepped forward, took a cigarette from her lips and stubbed it through the back of my blazer.

"The perfect round hole the cigarette burned seemed to sum it all up. All I was good for was stubbing out a cigarette. I was of no use to anyone."

She admits that school was the worst place for bullying: "You know how kids are. They're very quick to perceive a weakness and it was good fun to try to get a rise out of me, so they laughed at me and called me ugly names.”

As a result of the never-ending bullying Susan became shy and lost trust in everyone. She recounts that verbal and physical abuse inflicted upon her by bullies scarred her for life.

"When you're a child, grown-ups always tell you that 'sticks and stones will break your bones, but words will never hurt you'. I've never seen the logic of it. Cuts and bruises quickly heal and disappear. You forget about them. But the psychological wounds that bullies inflict with words go much deeper.

"Even now I don't like to think about those times too much, in case the scars begin to open up and hurt, making me feel useless all over again."

As a result of bullying in school she went through school without many friends. She spent much of her adult life living at home with her parents. But when her father died aged 8- in 1999 followed by her mother in 2007, aged 91 Susan found it difficult to cope with only her cat pebbles for company.

The star says she knew what people were thinking when she first walked onto the stage for her audition in Britain's Got Talent. "I knew what everyone was thinking. 'Just look at her! She's got a bum like a garage, a head like a mop, I'm not too sure if her teeth are her own and she's claiming to be a singer! She cannae sing. She cannae! So I opened my mouth and showed them what I could do."

The rest is history!