The chair of South Africa's governing African National Congress (ANC) has told an inquiry into state capture that corruption has been "a reality for a long time".

State capture refers to business people exerting undue influence on government officials to secure lucrative contracts.

ANC chairman Gwede Mantshe, who previously served as the party's secretary-general, also told the inquiry that the controversial Gupta family wanted the ANC to intervene in their dispute with South Africa's commercial banks.

The Guptas and former President Zuma have always maintained their innocence.

When asked what the ANC did when it realised that corruption was a reality, Mr Mantashe said the party made a "unanimous decision" to establish an independent body to investigate state capture at its elective conference last December.

Mr Mantashe was the most senior ANC official to give evidence at the inquiry.

He also said that the ANC wanted to help the inquiry find out "whether there were any irregularities, undue enrichment, corruption and undue influence in the awarding of contracts, mining licenses, government advertising in The New Age newspaper, any other governmental services in the business dealings of the Gupta family with government departments and state-owned enterprises".

President Cyril Ramaphosa is also expected to give evidence in the New Year.

The inquiry continues.