President Cyril Ramaphosa on Thursday refused to be drawn on his son's previous business dealings with African Global Operations, formerly Bosasa, as he answered questions in the National Assembly on the company that is at the centre of shocking allegations of corruption also involving members of his cabinet.

Democratic Alliance leader Mmusi Maimane wanted Ramaphosa to say exactly how much his son had benefited from his dealings with Bosasa.

"It's an easy answer. It's a fairly straightforward answer. The Public Protector is busy with this whole matter and all information has been submitted to the Public Protector by myself, a number of people as well as my son so the contract that he had for doing work for them outside the country is a matter that is now with the Public Protector and it is going to be dealt with in that way," Ramaphosa said.

"If you care to know, there is really nothing to hide."

MPs in opposition benches objected fiercely, insisting Ramaphosa quantify how much his son made in relation to Bosasa. The president would not bite.

Last year, during another question-and-answer session in Parliament, Ramaphosa said his son, Andile benefited to the tune of R500 000 from a contract with Bosasa. At the time, he said if there was any wrongdoing he would march his son to the nearest police station himself. Ramphosa later retracted his answer, saying he inadvertently provided incorrect information and that the half a million rand was in fact donated to his campaign to become African National Congress president.

While Ramaphosa has returned the money, Public Protector Busisiwe Mkhwebane was now probing the matter and has already interviewed the president.