Public Protector Thuli Madonsela on Monday claimed a senior ANC member leaked her letter to President Jacob Zuma to the media.

"She has been advised confidentially that it is a senior politician and member of the ruling party that leaked the confidential letter to the media, conduct she considers improper," her spokeswoman Kgalalelo Masibi said in a statement.

"The public protector reiterates her appeal to the media to refrain from peddling confidential documents released dishonestly as this tends to shift the focus from real issues."

The African National Congress was not immediately available for comment.

Madonsela's office was reacting to statements by the ANC and some of its alliance partners which she called "extraordinary and unwarranted attacks" on her.

Madonsela reportedly wrote to Zuma in a recent letter that he was second-guessing her recommendations following her investigation into the R246 million spent on security upgrades to his Nkandla, KwaZulu-Natal.

In her report, "Secure in Comfort", Madonsela recommended that Zuma repay money spent on upgrades not related to security, such as the swimming pool, cattle kraal, amphitheatre, and visitors' centre.

In his 20-page reply to her report, Zuma indicated Police Minister Nathi Nhleko needed to determine if he should repay any of the money spent on security upgrades at the homestead.

In her letter to Zuma, Madonsela wrote: "I am concerned that the decision you have made regarding the police minister gives him power he does not have under law, which is to review my decision taken in pursuit of the powers of administrative scrutiny I am given... by the Constitution."