Former communications minister Faith Muthambi has not applied to cross-examine acting Government Communication and Information System (GCIS) CEO Phumla Williams at the State capture commission of inquiry.

News24 has learnt that Muthambi was issued with a notice which informed her that Williams would implicate her. She was given 14 days to apply to cross-examine her, as stated in the commission's rules and regulations.

Commission spokesperson Reverend Mbuyiselo Stemela confirmed to News24 that Muthambi had missed the deadline, even though she had been notified.

"The rules of the commission do not give her an opportunity to [apply] to cross-examine anymore. She was notified on time that a witness will implicate her and given 14 days to respond as stated in the regulations," Stemela said.

Muthambi released a scathing statement on Tuesday lashing out at Williams and labelling her a liar, following her testimony on Friday and Monday at the State capture inquiry.

"Phumla Williams is one of the most shameful manipulators and liars that I have ever had the displeasure to encounter," Muthambi said in the statement.

"This is exactly the Phumla Williams I worked with, who couldn't pass the opportunity to tell a lie, any lie, to ingratiate herself with anyone in a position of authority and now panders to the most basest instincts of the public," she said.

Williams implicated Muthambi at the inquiry on Monday, accusing her of wanting to "steal at all cost" from the GCIS.

Williams told the commission that Muthambi rendered the GCIS dysfunctional during her short stay as the minister, at one point appointing a junior to act as the director general, bypassing three deputy directors general.

She said Muthambi had also stripped her of 70% of her functions as deputy director general, including her responsibilities over supply chain management and finances.

Williams also said Muthambi wanted to oust her because she wanted someone in charge of procurement and finances that "they could manipulate".

The commission has heard that R55-million was paid from GCIS to the Gupta-owned The New Age (TNA) newspaper when it sponsored the controversial SABC/TNA breakfasts. It is investigating allegations of undue influence by the politically-connected Gupta family over former president Jacob Zuma's administration.

Williams was appointed to act, after Mzwanele Manyi left the GCIS. She said her relationship with Muthambi, who is a known Zuma ally, strained just weeks after he appointed her after the 2014 elections.

Their battle started with Muthambi writing to her complaining that letters to her office had spelling errors, the wrong logo and she failed to address her as "honourable".

Williams said Muthambi also defied a Public Service Commission ruling that she must be paid an acting allowance as Cabinet spokesperson.

Muthambi has said in a statement that she watched Williams' testimony "with grave disappointment, and alarm".

She accused her of undermining the commission, by making it about herself. However, she did not directly respond to Williams' testimony.

Williams broke down on Monday, comparing the "torture" she endured under Muthambi to the torture she endured when she was arrested in 1988 by apartheid forces who wanted to turn her into an Askari.

She told the commission in harrowing details how Muthambi had "opened her torture scars".

"I was no longer sleeping, I had nightmares. I was reliving my situation. My facial twitches were back… I never thought in this government people can do such things," she said.

At one point, Williams wrote to Muthambi indicating her notice to apply for early retirement, but she rescinded it days later, declaring that Muthambi was the "enemy of the state and leaving GCIS would be letting the country down".

Muthambi said the details of her alleged torture were an attempt by Williams to emotionally manipulate the commission and the public.

"Her emotional self-serving outburst and entirely inappropriate attempt to refer ordinary managerial and management processes as similar to torture, and her experiences in detention is so deliberately emotionally manipulative, that it would have been laughable if her intentions in doing so were not so blatantly malicious and informed by an irrational (almost psychotic) hatred of me," she said.

Muthambi said she was seeking legal advice on the "extremely one-sided evidence laced with half-truths and blatant lies".

"It is unfortunate that such a prestigious commission is being compromised to hear matters that, if legitimate, should have sought legal address through human resources avenues or other appropriate legal channels, when these grievances materialised, which in this instance was many years ago."

Attempts to reach Williams for a response were unsuccessful.

Muthambi said she respected the commission to help "root out undue influence on any lever of the state."

"[Williams] has once again taken the opportunity to undermine an important institution to make it all about herself. This was the usual all-consuming sense of entitlement, the wilful distortion of the facts to paint herself as a victim, casting aspersions on her erstwhile colleagues, tarnishing the reputation of the GCIS and undermining the painstaking work it has undertaken under various leaders to establish itself as an apolitical instrument to further our democracy.

Meanwhile, Congress of the People (Cope) has called on the African National Congress to remove Muthambi from Parliament, describing her treatment of Williams as "inhumane and disgraceful".

"The damning evidence by Williams needs to be taken seriously. Serious actions against her torturer, Faith Muthambi, are needed," Cope spokesperson Dennis Bloem said in a statement.

"[The] ANC is put on a test. Let's see if they still have morals. For them to pass the test, they must immediately remove Faith Muthambi from Parliament, where she is called an honourable member. There is nothing honourable about her," he said.