The Zuma affair and ongoing controversy over the arms deal reinforced the argument that political parties' funding sources should be made public, Idasa analyst Richard Calland said on Wednesday.

Calland, manager of Idasa's Right to Know programme, was speaking at a Cape Town Press Club lunch. Idasa is about to launch a court bid to force the country's major political parties to disclose their funding sources.

"I think the arms deal case, and now the Zuma case, illustrate ... how business and its hidden hand can operate in a way that taints and contaminates the public policy process," Calland said.

He said secrecy over sources had given big business far too much influence in driving parties' policies, and that if there were more transparency about funding sources, those parties would be more answerable to the electorate.

His statements follow revelations this week that the African National Congress holds a ten percent share in Nkobi Holdings, a company of which Deputy President Jacob Zuma's controversial financial adviser Schabir Shaik is a director.

Nkobi is one of the companies that benefited from the multi-billion rand arms deal, and is now named in corruption allegations by the Scorpions.

Idasa last year asked political parties and 13 large companies to disclose funding information under the Promotion of Access to Information Act.

Though several parties said they supported the idea of increased transparency, none of them was willing to provide information about past funding.

Gencor was one of the few companies that was willing to disclose information on their donations.

With acknowledgements to Sapa and the Mail & Guardian.