Mavuso was testifying under oath before Parliament's ad hoc committee looking into the fitness of the SABC board on Thursday.

He said Muthambi's amendments, made after Hlaudi Motsoeneng had been named permanent chief operating officer in July 2014, gave the chief executive officer (CEO), the chief financial officer (CFO) and the chief operating officer (COO) powers to appoint group executive members.

The amendments needed the board's signature but only had Muthambi's, he said.

"The power to appoint group executives went from the board to the group executives," he told the committee.

"So the CEO, CFO and COO [now] appointed executive positions, and could 'merely inform the board' of their decisions."

Mavuso said he found it very problematic that the shareholder of the SABC, that is the minister, was taking responsibilities away from the board, therefore "usurping" its powers.

"It was very clear there was a solid line of divide between board members, which led to some of them resigning prematurely.

"Normally, it should have been done by the board. Whoever is coming into the next board, it will be an issue which has to be taken into account."

Mavuso said the CEO, CFO and COO were the only positions that required the minister's approval.

All the SABC's other group executives were appointed by the board according to the Broadcasting Act.

Ping pong, musical chairs

He said the results of Muthambi's amendment were that the SABC's group executive appointments become like a game of ping pong or musical chairs.

"What has been the practice is people have appointed from within. We never saw an advert.

"It may have been internally [promoted], but never external."

He said it required certain political muscle to resolve this issue.

ANC MP Fezeka Loliwe was asked why he did not quit sooner during his three-year stay as a board member, given his seemingly principled character.

"Honourable member, I'm not a quitter. I believe in fighting until sanity prevails.

"But in this instance, I think I became insane as well. It reached a point where it was just too much."

Mavuso resigned publicly from the board on October 5, along with Krish Naidoo, during a sitting of Parliament's portfolio committee on communications.

The committee meanwhile will interview Naidoo, former acting GCEO Phill Molefe and former group executive for risk and governance Itani Tseisi on Friday.