Bongi Ngema Zuma: 'I chose to be his fourth wife'

The South African President, Jacob Zuma, has wrapped up the ANC's week-long conference with a speech promising to crack down on corruption and end the infighting within the governing party.

He has come in for a fair deal of criticism himself though, not least because of the amount of money spent on his residences and his four wives.

Most prominent among them is Bongi Ngema Zuma - she is the wife who accompanies the president on trips abroad.

And she has been active in promoting her foundation that fights diabetes.

At her presidential residence in Pretoria, the BBC's Lerato Mbele asked what her duties entailed.