The PR firm Bell Pottinger has often courted controversy with its choice of clients; they represented the Paralympian Oscar Pistorius after he was charged with murder, Asma al-Assad the Syrian first lady, and the Pinochet Foundation, whilst the former Chilean dictator was being detained in Britain.

But the latest crisis the company faces could be the most challenging yet - they stand charged of fomenting racial tensions in the tinderbox of post-apartheid South Africa. In his first broadcast interview following the scandal, the CEO of Bell Pottinger is adamant that this was never their intention.

Manveen Rana has the first of four special investigative reports across the week.

(Photo: Demonstrators protesting against the South African president. Credit: Getty Images)