She has made a £560million fortune and is famous throughout the world for creating the world's most famous boy wizard.

But almost twenty years on, author JK Rowling is tormented by the fact her sick mother never knew of her success.

Miss Rowling's mother Anne died six months after she started sketching the first tales of Harry Potter.

Regrets: JK Rowling never got to share the huge success of the Harry Potter series with her late mother

Her daughter never told her that she had started writing the stories that would eventually become a global phenomenon.

The children's writer told a BBC Scotland documentary to be screened tonight that her 45 year-old mother's death from multiple sclerosis (MS) in 1990 had become a 'real regret'.

The 42 year-old, who has sold more than 400 million Harry Potter books worldwide, said: 'I started writing Harry six months before she died. That's obviously a real regret, because I never told her I was even writing it.

'She knew I wanted to write - I'm not sure how seriously she took it.

'She never knew anything about Harry Potter at all.'

Edinburgh-based Miss Rowling - who is patron of the Multiple Sclerosis Society Scotland - witnessed her mother's gradual decline from the disease.

She explained: 'She had me very young. She had me when she was 20, so I was 25 when she died.

'When I left home, she was walking unaided. By the time I graduated, she was in a wheelchair and in the house she needed a walking frame.

'It was awful to watch.'

Miss Rowling's mother was diagnosed in 1980 after numbness in her right arm sent her to a GP.

She is thought to have suffered from the disease for a further six or seven years beforehand.

The writer said: 'Then a year later, this numbness had spread over half of her torso.

'It took her over a year to go back and this time she was sent to see the neurologist who had done the first tests.

'She expected to be told she needed more tests and he just said, 'Well, you've got multiple sclerosis'.'

Miss Rowling's first book Harry Potter and the Philosopher's Stone was not published until 1997.

In 2006, Miss Rowling donated £2million to help set up a multiple sclerosis research centre at Edinburgh University, in the hope of finding a cure through stem cell reserach.

Current drugs can only target inflammation caused by the disease.

She criticised the lack of interest and funding given to the condition which affects an estimated 85,000 people in the UK.

'She said: 'It's a Cinderella of illnesses, you hear this all the time, because it's under-funded, because it's ignored.

'I think that it's possibly common to a lot of neurological conditions. It just seems to be an area that has not seemed very sexy for funding.

'People get diagnosed and sent home. It's a frustration to those of us whose family members do have MS that so little is being done, because it is a life-altering condition and a lot can be done now, so why isn't that happening?'

MS is a condition of the central nervous system that impairs the brain's ability to transmit instructions to the muscles. There is no known cure for the disease.

Last year £5.6 million was spent on research compared to £315million on cancer research.

After her mother's death Miss Rowling moved to Oporto in Portugal to teach English as a foreign language.

There she met Jorge Arantes, a trainee Portuguese TV journalist.

They married in 1992 and had a daughter, Jessica, but the marriage collapsed after 13 months.

Mother and daughter then moved to Edinburgh the location where Rowling continued to write the Potter series.

She now has seven Potter novels and five Hollywood films to her name.

The documentary, Scotland's Hidden Epidemic: The truth about MS, is broadcast on BBC Scotland at 10.45pm tonight. It will be available outside Scotland on digital television and online.