This comes in the wake of Moyane threatening to take Zikalala to court, following his allegation on Power FM on Wednesday.
Zikalala is one five ANC stalwarts who penned a discussion document on counter-revolution and state capture, and used Moyane as an example of functionaries who incapacitated the state.
The stalwarts included Wally Serote, Aziz Pahad, Thami Ntenteni and Fazel Randera.
Speaking to Daily News on Thursday, Zikalala said while he could not allege that Moyane was a spy, he could have been used by apartheid agents, and that his credentials were questionable.
“As veterans, we cannot go around saying people are spies without evidence, but what we are saying is that his credentials are questionable.
“How he left the country, and what he has been doing makes him questionable. This warrants a thorough investigation by the ANC,” Zikalala said, adding he was not fazed by Moyane’s threat to take legal action against him over his remarks.
“I am not fazed by his intention to take me to court. He must take the whole document to court. The manner in which he went into exile with a suitcase, books, new clothes and flew by plane was questionable.
“It was very suspicious. Going into exile was not a nice journey, like his,” he said.
Zikalala said Moyane could have even dramatised his experiences in exile, and lied about his alleged attack in his house because there was not a shred of evidence to his claim.
“When we tried to look at that, there was no trace of the claim whatsoever,” Zikalala said.
He accused Moyane of having been groomed to dissipate Sars.
In their document, the stalwarts cited the Nugent report into Sars, and said Moyane had been trained by Bain SA to head Sars, a year before former president Jacob Zuma announced his appointment.
“Bain knew a year before he was appointed that Moyane would become the head of Sars. It therefore trained Moyane about what he should do once he took over at Sars,” the stalwarts said.
While Moyane referred all questions regarding the allegations to his lawyers, he took to social media and threatened to drag Zikalala to court.
“Although the comments are of course irresponsible and baseless, they are serious. I have engaged my lawyers with the intention to serve Mr Zikalala with legal papers,” Moyane said.