Zindzi Mandela, daughter of former South African president Nelson Mandela, at <i>Mandela: Long Walk to Freedom</i> premiere in London.

Zindzi Mandela, daughter of former South African president Nelson Mandela, at Mandela: Long Walk to Freedom premiere in London. Photo: Reuters

In an eerie twist, Nelson Mandela died at almost the precise moment VIPs, including his daughter Zindzi and Prince William and Duchess of Cambridge, were walking the red carpet in London to attend the premiere of the film Mandela: Long Walk to Freedom.

South African president Jacob Zuma announced that Mandela died surrounded by his family on Thursday at 8.50pm local Johannesburg time.

Britain's Prince William and his wife Catherine, Duchess of Cambridge, at the premier of <i>Mandela: Long Walk to Freedom</i> in central London.

Britain's Prince William and his wife Catherine, Duchess of Cambridge, on the red carpet for Mandela: Long Walk to Freedom in central London. Photo: AFP

That was 10 minutes before the screening of the widely praised and sold-out biopic in Leicester Square.

Also in attendance were Idris Elba, who plays Mandela in the film and Naomie Harris, who plays the former South African president's wife, Winnie.

Mandela's daughter Zindzi had told reporters on her way into the cinema that her father was still doing well.

"My father is fine," she said. "He's 95 years old and he is pretty frail. We are hoping to see more of him."

Ms Mandela said she had approved of the clips of Mandela: Long Walk To Freedom she had seen before the premiere.

"I love it. I think it's authentic," she said.

William, with a solemn Kate by his side, paid tribute to Mandela as he emerged from the theatre.

"It is extremely sad and tragic news. We are reminded of what an extraordinary and inspiring man Nelson Mandela was," he said to waiting media.

Long Walk to Freedom traces Mandela's life from his childhood in a remote rural part of South Africa, through his years struggling against apartheid, to his 27 years imprisonment and his election as the country's first black president in 1994.

In the week before his death, the film has already become South Africa's highest grossing picture, earning $US427,000 ($A471,380) in its opening week, according to Videovision Entertainment.

The British-South African co-production opened just over a week ago in South Africa, followed by a limited engagement in New York and Los Angeles.

Mandela: Long Walk to Freedom will be released in Australia on February 6 2014.

- with agencies