The philanthropist and co-founder of Microsoft, Bill Gates, has paid tribute to Nelson Mandela and says he will remember the former South African president most for raising awareness of HIV.

Tributes have been pouring in for Mandela, who died on Thursday at the age of 95.

His death was announced yesterday evening by South African President Jacob Zuma.

Bill Gates said: “Melinda and I admired Nelson Mandela, as the world did, for his courageous stand against apartheid. But we came to know him personally for a different reason: the fight against HIV/AIDS.

“He was especially powerful in speaking out against stigma. In many countries, especially in the early years of the HIV epidemic, there was a lot of misinformation about how the virus was passed. Some people were afraid to touch a person with HIV.

“President Mandela knew how damaging that was. He knew it made fighting the epidemic harder, and it wrecked the lives of people suffering from the disease. He also knew the stigma was just based on fear and ignorance. He thought he could make a difference by teaching people the facts.”

Mr Gates added: “This was something we talked about a lot every time we met: How could we fight stigma and spread reliable information about the disease?”

Earlier on Friday, the Acting Chief Executive of Terrence Higgins Trust, Paul Ward, said he had been personally inspired by Nelson Mandela’s “compassion” and advocacy when it came to the issue of HIV.

“Whenever he addressed a World AIDS Conference, no one could fail to be moved to action. The ideals he stood for – freedom, compassion, and the universal human right to love, life and happiness – struck a chord at a time when people with HIV, myself included, were facing unacceptable levels of prejudice and discrimination,” Mr Ward said.

However, Mandela’s record on HIV is not without criticism.

Several commentators, including human rights campaigner Peter Tatchell, believe Mandela was initially slow off the mark in responding to South Africa’s HIV epidemic during his term in office.

Writing for PinkNews.co.uk, Mr Tatchell said: “His government failed to make anti-HIV drugs widely available. Earlier and stronger action would have saved tens of thousands lives. His later public statements on HIV were welcome but they came years too late.”

Some of those close to Mandela have suggested that the former president became such a highly active and vocal HIV campaigner in his later years because he regretted failing to spend enough time on the issue whilst in office.

During the 1994 election, he told the BBC: “I wanted to win, and I didn’t talk about AIDS.” Once he was president, Mandela said, he “had not time to concentrate on the issue”.

As Mandela grew older and more fragile, he gave up all engagements except those at which he was invited to speak on HIV and AIDS. It became the most important work of his foundation.

In 2005, Mandela announced that his only surviving son, Makgatho Mandela, had died from an AIDS related illness.

Mandela had been unaware of his son’s HIV status until the previous June, six months before his death. Telling the world that Makgatho had died of AIDS was seen as an act of great importance.

“Let us give publicity to HIV/AIDS and not hide it, because the only way to make it appear like a normal illness like tuberculosis, like cancer, is always to come out and to say somebody has died because of HIV/AIDS. And people will stop regarding it as something extraordinary,” Mandela said.

Mark Heywood, of the Treatment Action Campaign in South Africa, said: “I think Nelson Mandela has been one of the most important voices on AIDS in South Africa and in the world. He has used his reputation and his energy to stress how fundamental this is to the future of our country and the developing world generally.”

According to Medicine San Frontières, an estimated 5.6 million people are living with HIV in South Africa, the highest figure worldwide.