Sammy Gitau defied the odds to get from Mathare to Manchester

Sammy Gitau was initially refused a visa to attend the UK university as he had only two years of formal education.

He grew up in crime-ridden Mathare slum in the Kenyan capital, Nairobi, where from the age of 13 he was the family breadwinner after his father's murder.

He sold drugs and battled addiction before turning his life around.

'Slum potential'

The University of Manchester describes his achievement in winning a master's degree as "a miraculous journey".

"It feels wonderful; it feels wonderful," Mr Gitau told the BBC's Network Africa about receiving his MSc degree in international development project management.

I will go back and stop children going through the same kind of life as me

Sammy Gitau

"It makes me look back and see myself, see those difficult times, and also, importantly, realise we have potential people in the slums.

"We have other people who are just like me."

Mr Gitau, 35, once came close to death after a drugs overdose and said it changed his life.

"After the drugs put me in a coma, I remember hearing hospital staff telling me I was going to die and when you are dying, you make a deal with God," he said.

Mathare is crime-ridden slum in the centre of the Kenyan capital

"You just say, 'Get me out of here and I will do anything. I will go back and stop children going through the same kind of life as me.'"

Once out of hospital he began a project to help children in the slum where he grew up.

Mathare is the most crime-ridden of all Nairobi's slums where organised outlawed gangs reign supreme.

Mr Gitau's community resource centre used donated containers as classrooms and with three volunteers taught children skills like carpentry, tailoring, computer skills and baking.

It costs $100 a month to run and is estimated to have helped some 20,000 slum children.

This work brought him to the attention of European Union officials working in Kenya, who, on hearing of his dream, helped him apply to the University of Manchester's School of Environment and Development.

The university decided his vast experience on the ground made him eligible to study and paid his course fees; his living costs were funded by charitable donations.

"I found it humbling to teach Sammy - it really is a remarkable achievement," the University of Manchester's programme director Pete Mann said.

Mr Gitau says he will continue to direct his education and his energies at improving life for others in Mathare slum.