Former president Jacob Zuma's lawyer Dan Mantsha has accused the State capture commission of inquiry of asking his client questions with an intention to "attack his credibility".

On Wednesday, Deputy Chief Justice Raymond Zondo adjourned proceedings until Friday after Zuma's legal team complained that their client had been brought in under false pretences. 

Zuma's legal team threatened to withdraw him from testifying, with advocate Muzi Sikhakhane SC saying that his client was being cross-examined on hearsay testimony.

Zuma's legal team complained that evidence leader advocate Paul Pretorius SC was focusing on smaller details of former minister Barbara Hogan's testimony that he had interfered to appoint Siyabonga Gama into the position of Transnet CEO.

Speaking on the sidelines, Mantsha said the commission should not put any questions to Zuma that amount to cross-examination.

"He [Zuma] was asked questions with an intention to attack his credibility. The president was never an operational person in terms of the issues that they ask him on."

He said the commission was not acting according to its own rules, adding that Zuma should be treated like any other witness who has appeared before Zondo.

Mantsha also accused the commission of unfairness and bias, saying it wanted to treat Zuma as a "king of the so-called State capture".

"He elected not to engage in gossip with people he has fired. If the commission sticks to the rules, then the former president will still appear before it. The president is here because he respects the citizens who have elected him before.

"The former president made it very clear on Monday that this commission is part of the agenda which [was] started against him in trying to finally bury him, and he went further to say this commission was started as a regime change to remove him from presidency," Mantsha said. 

Zuma objected to being cross-examined when Pretorius wanted to question him about Hogan's statement to the commission.

But Zondo explained that, just because Zuma had answered something, it did not mean that that was the end of it.

He added that the commission had to weigh up all the evidence and ensure it had a full picture. 

The former president started giving testimony on Monday, kicking off his appearance with a lengthy statement in which he claimed there was a long running plot against him. 

On Tuesday morning, he said his personal assistant had received a call following his first day at the inquiry, with the person on the other end telling her they were going to "kill" Zuma, his children and the people around him.