By Martin Plaut BBC, London

Tucked away in the narrow lanes of central London, in a nondescript office block, is a law firm that has managed to change the lives of some of the poorest people in Africa.

Mr Day says that his law firm works on a no-win no fee basis

Martyn Day is one of the senior partners in Leigh Day - a firm that has fought three path-breaking cases on behalf of thousands of African clients.

"People in the developing world are often treated terribly. They needed some route to justice," says Martyn Day.

Mr Day won, on Tuesday, legal aid for 650 Kenyan women who say they were routinely raped by British army.

Earlier this month he won a final settlement for seven thousand South Africans from Cape plc - a British company which mined asbestos in the remote northern Cape.

Before that he won a settlement from the British army for hundreds of ethnic Maasai who were injured by unexploded bombs left behind on a Kenyan training range.

'Treated terribly'

So why does Martyn Day do it?

"I lived in Africa - in Zimbabwe and Zambia - from the age of 13 and travelled in the region," he says.

"My partner, Richard Meeran, married a South African.

When they find that there are lawyers who are prepared to represent them it means that at last for them justice has been done Martyn Day

"So we decided some time ago that we should put our abilities towards pursuing claims for injured people against British multinationals and the British Government abroad.

"We met with organisations like Amnesty International in the mid 1990s and said we were prepared to travel abroad to take up cases of people injured by companies or the government.

"The cases arose from that."

Martyn Day believes that Africa has been treated terribly by British companies and sometimes by the British Government.

"It is so easy to do things and for them never get noticed. That's why we have taken up these cases," he says.

No-win, no-fee

One of their biggest achievements was to persuade courts in Britain that they should accept cases outside the country. This broke legal ground.

So did the fact that they managed to win British Government funding, known as legal aid, to pay for the cases.

Martyn Day says this is vital. Otherwise they have to work on a no-win, no-fee basis - when they get paid on an hourly rate - but only if they win.

'Most of the people have been so used to being downtrodden by life,' says Mr Day

"We are a private company employing about 100 people. They have to be paid," he says.

But what does it mean for Martyn Day when he is able to go back to Kenya or South Africa and report that he has won a case?

"When I go back to Africa and meet the people I represent it is a fantastic experience.

"Most of the people have been so used to being downtrodden by life, whether they have been raped, bombs have gone off, or they have gone down with asbestosis.

"When they find that there are lawyers who are prepared to represent them it means that at last for them justice has been done. It is very rewarding."