Photojournalist Don McCullin took portraits of Africans living with HIV/AIDS for a Christian Aid exhibition called Cold Heaven.

McCullin says the publications for which he took his war photographs may have paid him, but his sense of duty was to the people he saw suffering, and he did his best to portray their humanity, however degrading the circumstances.

Many journalists and photographers become addicted to the heightened consciousness of being alive that they feel from working in wars, but most build up a protective coating of cynicism.

McCullin's personal moral code propelled him to seek out work that would focus attention on AIDS in Africa.

Christian Aid was enthusiastic when McCullin, now aged 65, approached them to see if he could collaborate, but had no way of covering his costs.

He raised his own funds from the Kaiser Foundation, a U.S. philanthropic organisation focusing on health care issues.

When he travelled to some of the African countries devastated by AIDS, what he saw was much worse than he had expected.

"I've been to Biafran wars, and seen famines and earthquakes," he said. "You name it, I've seen it. But there was a silent, creeping looming death for millions of people."

McCullin visited people's homes, talked his way into hospitals and was taken to hospices, orphanages, schools and home-based care projects supported by Christian Aid.

He was struck by the disease's impact on families, and visited homes where children as young as three were caring for sick parents.

He said: "I totally focused my leaning towards the children and parent angle because that is the most serious side of it. Already there are millions of orphans in Africa. Who should grow up without both parents? Nobody, I think."

In many African communities where AIDS has cut a swath through the young adult population, the older generation is caring for its grown-up children and their children.

"Most grandparents in all worlds are pretty closely linked to the poverty structure of life, because of their lack of earning power, but to find two grandparents who are alive in their late seventies and early eighties having to look after 16 grandchildren was beyond your imagination," said McCullin.

McCullin was outraged at the inequality in Zambia: "There's money pouring into that country from American-based mining companies, and yet you've got the poorest people in the world lying on floors of mud huts dying of AIDS.... The World Bank is supporting this rejuvenation of the copper industry. Where's the money going to?"

He visited Botswana, which is rich in diamonds but has the world's highest incidence of HIV. More than 35 percent of the country's adults are HIV-positive.

Botswana's President Festus Mogae has set himself up as a leading African voice urging changes in sexual behaviour to combat HIV/AIDS, but McCullin found the authorities uncooperative.

"It's a rich nation. We went into one of the most beautiful hospitals in the world, let alone Africa. I barely got in there, because they tried as much as they could to lock me out."

After his first trip for the AIDS project, McCullin was not satisfied with the images he had made. "I went back this year because I was disturbed to think that my work wasn't strong enough and I still had more to see."

He found that the way to photograph people whose lives are dominated by terminal illness and stark poverty was to make family portraits.

Carefully posed with the subjects looking directly at the camera, McCullin's portraits focus on the humanity in people who have next to nothing, a statement that they and their homes are fitting for this classic form of photography usually reserved for celebrities.

McCullin said: "I did it that way because I wanted to offer these people some dignity. I didn't want to be taking advantage of wretched people dying on the floor. I wanted to become their voice in a way."

In one, a woman looks directly at the camera with eyes full of bitterness at her deteriorating body. A child on each side of her, the little girl on her right shines with the potential of youth, despite the circumstances.

He is very clear that his interest in HIV/AIDS in Africa was to raise consciousness, rather than merely a theme for his latest show.

"Being a photographer is not a big deal for me. I wasn't seeking any reward, and I wasn't seeking to make a name for myself. I've already done that, so I was doing it purely as a charitable exercise, to hope that someone could do something that maybe somebody else could survive out there."

McCullin has a strong -- almost naive -- sense of justice for someone who has witnessed so much destruction and inequality.

He wrote in his 1990 autobiography "Unreasonable Behaviour" that he had been haunted all his life by an emaciated albino boy whose photograph he took in Biafra in the 1960s.

"AIDS has killed as many people as Joseph Stalin and Adolf Hitler did between them during the last great war. How can you turn your back on the possibility of 40 million people dying with the AIDS crisis in Africa?"

But he has no illusions that his photographs on their own will bring about change. "You can only scratch the surface of the earth in terms of what you try to do in any conflict, any situation. It's not people like me that can do anything."

The photographs will be transferred to the U.N. headquarters in New York for an exhibition to be opened by Secretary-General Kofi Annan on June 25 to coincide with a conference on AIDS, a source of pride for McCullin.

"So my scratches are getting slightly deeper...I could do this work for the rest of my life, until we got some doors kicked in, not just opened."