It was nearly two months since 'Mandela: Long Walk to Freedom' was offered the prestige of being the subject of the annual Royal Film Performance, at which the royals - in this case William and Kate - give a film their royal stamp of approval.

However, the evening took an unexpected turn when Nelson Mandela's death was announced while the film was being screened.

Even his daughter Zindzi Mandela seemed to be unaware her father's health had taken a turn for the worse on the red carpet prior to the screening.

SOUNDBITE Nelson Mandela's daughter, Zindzi Mandela (English), saying:

"He's only seen clips. We're hoping to show him the film sometime soon." Reporter: "How is he doing?" "He's fine, thank you. He's just old. Thank you for that."

When the film had finished, Prince William was one of the first to offer a reaction to the passing of the former South African president.

SOUNDBITE Prince William (English), saying:

"Obviously it's extremely s