Finance Minister Nhlanhla Nene told the state capture commission of inquiry that his December 2015 axing was linked to the nuclear build programme which then president Jacob Zuma sought to finalise.
This is the first time a member of Cabinet has appeared before the commission, headed up by Deputy Chief Justice Raymond Zondo.
Here are some of the revelations which emerged during his testimony:
1. Nene said he twice refused to sign off a nuclear deal with Russia because it would have had severe financial implications for the country. He first told former energy minister Tina Joemat-Pettersson that he would not sign off a deal for Russia to provide South Africa with nuclear energy, because it lacked a feasibility study and there were unknown cost implications. He asked her to rewrite the letter, but still refused to put his signature on it.
2. Nene also told the commission that his own colleagues were hostile towards him after he refused to sign off the deal and said rural development minister Maite Nkoana-Mashabane and former minister David Mahlobo accused him of insubordination.
3. Nene also said his Russian counterparts knew very little about the deal and added that, when he questioned them, they told him they were aware of the deal but were not privy to the details.
4. The finance minister admitted that he continued visiting the Guptas' Saxonwold home in 2014, even after National Treasury undertook to investigate the family for the Vrede dairy farm deal with the Free State government.
5. Nene also insisted that he responded to questions the EFF sent to him. The party claimed he ignored questions sent to him through a parliamentary process. Nene even questioned the timing of the EFF's claims linking him to the Guptas, saying he believed it was because he was due to appear before the commission. He denied claims that he assisted with the facilitation of any business deals for the Guptas with the Public Investment Corporation while he was a deputy minister.