Johannesburg - The ANC on Tuesday denied any involvement or knowledge of the transaction between Hitachi and its investment arm Chancellor House.
"The ANC categorically states that the organisation was not involved, implicated nor approached to answer on anything relating to the charges brought against Hitachi," treasurer general Zweli Mkhize said in a statement.
"The ANC was further not involved in the transaction between Hitachi and Chancellor House, nor do we have any information on any impropriety relating to the award of the Medupi or Kusile contracts to Hitachi."
Mkhize said the ANC would therefore not be able to comment on what he called "matters internal" to the two parties.
Hitachi is the company that won the tender to provide Eskom with boilers for the Medupi and Kusile power stations.
Chancellor House used to have a 25% stake in Hitachi Power Africa, the Tokyo conglomerate's African subsidiary.
Calls for the ANC to divest from the company go back as far as 2010 and in March last year it was announced that Chancellor House had sold its stake in the company.
On Monday, the US Securities and Exchange Commission announced that it had charged the Tokyo-based conglomerate with violating the Foreign Corrupt Practices Act.
It claimed that Hitachi Ltd had "inaccurately recorded improper payments" to the ANC in connection with contracts to build two multibillion-dollar power plants.
Hitachi was aware that Chancellor House was a funding vehicle for the ANC.
The commission's complaint was filed in the US District Court for the District of Columbia.
ANC 'committed to clean governance'
Following the announcement, DA leader Mmusi Maimane vowed to lay a criminal charge against Chancellor House in Cape Town on Wednesday.
He would also write to Public Protector Thuli Madonsela, asking her to investigate.
Mkhize said the ANC was committed to clean and accountable governance and its national executive committee was directed to avoid all possible conflict of interest when raising party funds.
This was why it welcomed Chancellor House's decision to divest from Hitachi Power Africa, he said.
There were complaints from opposition parties that the ANC was controversially benefiting from stated-funded contracts through Chancellor Houses's stake in Hitachi.
At the time, opposition parties demanded that the company stop doing business with government.
Mkhize on Tuesday said the ANC was discussing ways of regulating party funding coming from the state and the public sector.
"We will study the outcome of the SEC matter and from that process identify appropriate lessons or actions, if any, to be taken," he said.