South Africa election: DA's Zille denies Mazibuko rift
12 May 2014 Last updated at 12:28
Ms Mazibuko was the first black person to lead the DA's parliamentary caucus
South African opposition leader Helen Zille has denied that her party's most senior black leader in parliament has quit because of differences with her.
Lindiwe Mazibuko, the Democratic Alliance's (DA) parliamentary leader, said she was going to study in the US.
Ms Mazibuko differed sharply with Ms Zille last year over whether the DA should support affirmative action.
The party got 22% of the vote in May's general election, the first since the death last year of Nelson Mandela.
He was elected the South Africa's first black president in the country's first democratic polls 20 years ago.
The governing African National Congress (ANC) won with 62% of the vote - its fifth consecutive victory since black people obtained the vote in 1994, ending white minority rule.