Former South African president Nelson Mandela is now reportedly on life support in a Cape Town hospital.

Various media organisations, including the US broadcasters CBS and CNN and the Huffington Post, are reporting the apartheid leader's has been placed on life support.

"BREAKING NEWS: Fmr. South African President Nelson Mandela has been placed on life support, @CBSNews confirms," CBS tweeted.

But there has no official statement.

The last update from South African president Jacob Zuma on Wednesday night said Mandela's condition remained unchanged in hospital and doctors continue to do their best to ensure his recovery, well-being and comfort.