Just 15 minutes before the end of the film 'Mandela: Long Walk to Freedom', based on the autobiography of the same name, Singh got the news that Mandela had died.
What was expected to be a standing ovation for Singh and the cast of the film from the celebrity audience, including Prince William and his wife Kate, turned into shocked disbelief as he waited for the end of the film to give the audience the tragic news and called for a minute's silence to honour the global icon.
A planned after party was also cancelled as cast left in tears.
Singh had spent almost two decades planning the multi-million rand film, which has been winning accolades all over the world.
Earlier, he explained how he had told Mandela after first reading the manuscript for the book that it had to be made into a film.
Singh also explained how it had been a huge challenge to condense the book into a film of less than three hours rather than a mini-series.
On Friday, cinemas halted screening of the film as a mark of respect, but since restarting it on Saturday, there have been reports of full houses, with some shows being booked out for the next fortnight already.
US President Barack Obama also hosted a special screening of the film at the White House last month.
