Beverley Naidoo: The long journey from Jo'burg

Opposite me in a meeting room at Penguin Books in Kensington sits a neat, slight, open faced, grey-haired woman in her late fifties. Dr Beverley Naidoo could be an active granny drawn to illustrate one of her own language books, although that's just the sort of blinkered labelling she detests.

You could sit beside this gentle woman on the Tube without suspecting that she has just won this year's Carnegie Medal, Britain's most coveted prize for a children's book – or that her winning novel, The Other Side of Truth (Puffin, £4.99), is a moving and challenging tale of young Nigerian asylum seekers, alone in an inhospitable London.

"Those of us who have been through the South African experience have a responsibility to speak out against injustice," she declares. Those calm eyes begin to blaze; she's fierce, passionate and expansive. And not just about "racism", around which she insists on inverted commas, "because there is only one race: the human race". She also means discrimination on grounds of gender, disability, social class, or any orientation: "Anyone who writes this off as 'political correctness', and therefore dismissible, is just copping out of thinking about the real issues."

The daughter of a Jewish mother and a practising Anglican father, Beverley Naidoo attended a sheltered all-girls, whites only, convent school in Johannesburg in the 1950s. "No one at home or at school ever acknowledged the injustice of the apartheid system," she says. "Mary was our cook, cleaner and nanny. As a child I never questioned the fact that I called her by her first name when all white adults had to be called Aunty, Uncle, Mr or Mrs. I never questioned that we called her by an English name when her first language was Tswana. I never questioned that her children lived 150 miles away, and she only saw them when our family was on holiday.

"One awful day, when I was about 11, she received a telegram and collapsed in front of me. Two of her three young daughters had died of diphtheria, a disease against which I, as a white child, had been vaccinated. Her children had not."

Some 20 years later, she used Mary's story as the basis for her children's novel Journey to Jo'Burg, in which she told young readers the harsh truth about life for black South Africans under apartheid. It was banned there until 1991.

Once she had left school, Naidoo saw "the other side of truth" for herself. "My frugal mother sent me each day with sandwiches to the local university. I used to eat my lunch on the grass outside the library. There I got the beginnings of a real education because there were a still a few black students about and we talked. My brother and I both got involved with Kupugani, a non-profit making food distribution organisation, which took me into Soweto." The crackdown soon came: "We were both arrested in the Big Swoop of 1964 and, aged 21, I spent eight weeks in the white section of Pretoria Jail". Her brother was sentenced to two years.

She tried to re-establish contact with her friends, only to find that the resistance to apartheid had been effectively smashed. So, financed by a UN bursary, she came to Britain to study English at the University of York and qualify as a teacher. Apart from a brief "licensed" visit in 1983 to see her dying father, she did not return freely to her homeland until 1991.

Plans to teach in Nigeria were abandoned at the eleventh hour. "I met Nandha Naidoo, a black South African exile and the man I wanted to spend the rest of my life with." She grins. "So of course I wanted to stay in London to be with him." She taught at an East End primary school and then in the "remedial" department of a secondary school in Brent. Later, while her two children were young, there were part-time advisory jobs in the Inner London Education Authority, before the family moved to Dorset in 1985. Beverley and Nandha still live there.

She found injustice in British schools. She recalls a headmaster who bullied and beat a child and another who cavalierly disregarded all the children he regarded as "remedial". She has now retired from teaching. Angrily amazed by the number of untruthful books about non-white cultures still in circulation, she took a PhD at Southampton to study the representation of racism in literature in the mid-1990s. Today she works full time as a writer.

"Fiction is such a wonderful process for opening doors," she says. "When I wrote Journey to Jo'burg, I wanted to tell a story from the point of view of the child I'd never been." Two sequels followed, and then illustrated books for children learning English as a second language.

Her books are lively literature. Beverley Naidoo is no formulaic promoter of "issues" thinly disguised as fiction. The Carnegie medal goes to a book which "provides inspiration" and a sense of "extended knowledge and emotional capacity". The Other Side of Truth certainly does that.

I tell her I live in port-girt Kent, bastion of xenophobic hysteria about "scrounging foreigners". We agree that politicians should be leading people to find ways to live; but they aren't. "Britain has a strong strand of decency," she says, "but it's also dogged by small-island mentality." The gut-wrenching plight of Sade and Femi could be that of any two kids. That why it's so horrifying. Few of us see the truth. We see only our own presumptions and prejudices.

An impassioned believer in the power of fiction to educate and develop, Beverley Naidoo is enraged and alarmed by the reductive trends in British education. She is furious about Longman's attempt to publish a "classroom version" of Journey to Jo'burg, in which the narrative is interspersed with chapter summaries and questions. "Literature is being turned into comprehension exercises," she says. The National Curriculum has "done a huge disservice to books and reading... Yet fiction deals with the whole of human experience. This functionalist box-ticking approach won't help anyone to make connections."

She begins to pack up her papers. "Do we really want this superficial, quasi-American approach?" she asks over her shoulder. "The power of the human sprit – which brought so many people through apartheid – is what we have to hang on to."

Beverley Naidoo, a biography

Beverley Trewhela was born in Johannesburg in 1943 of white South African parents. An opponent of apartheid, she spent eight weeks in jail before moving to Britain for higher education. Initially in London, and later in Dorset, for the next 30 years she taught, undertook educational advisory work, married Nandha Naidoo, raised two children and was an activist for the Defence and Aid Fund for Southern Africa. Journey to Jo'Burg (1985) was followed by 10 other books; she now writes full-timeThe Other Side of Truth (Puffin), winner of this year's Carnegie Medal, deals with young asylum-seekers in London. Her latest book, Out of Bounds (Puffin), comprises short stories about young people's choices during the half-century of apartheid. She is now writing a sequel to The Other Side of Truth.