The presidency on Monday declined to comment on a press report that, until he was served with a legal warning, President Jacob Zuma failed to respond to Special Investigating Unit (SIU) questions on his Nkandla home.

"That is not a matter we would comment on," presidential spokesperson Mac Maharaj said from New York.

"The issue is that the report is completed and has been given to Parliament. Now the issue is the content, and it becomes one of the reports before the parliamentary ad hoc committee."

Beeld reported on Monday that Zuma was one of two recalcitrant third parties whose lack of cooperation delayed the SIU's final report into misspending on his private Nkandla home by some three months.

It said the president finally responded on August 8, and only after he was put on terms by the anti-corruption unit, which was authorised to probe the Nkandla controversy in December last year.

"The SIU struggled for months to enlist the president's cooperation in its investigation into the Nkandla project of R246-million," Beeld and Die Burger reported in the article.

"Zuma was the very last official to answer the SIU's questions."

According to page 235 of the SIU's final report: "As we were required to do, we sought responses from the third parties. Not all were prompt with their responses.

"In fact, in respect of two of these parties, we had to formally put them on terms. The last response was received only on August 8, 2014."

Still on that page, the SIU adds that "a further major stumbling block to the earlier finalisation of our investigation was the fact that we were allowed access to the Nkandla complex only on July 3, 2014".

Both issues were raised by SIU head Vas Soni when he addressed Parliament's justice portfolio committee in July.

At that briefing, Soni expressed frustration at the delays, as well as concern that it was becoming an embarrassment for the unit.

The final report, which was submitted to Parliament this month, explicitly seeks to counter a perception that the unit deliberately delayed its findings to ease pressure on Zuma to respond to Public Protector Thuli Madonsela's report on Nkandla, which was made public in March.

"Such delay, the media suggested, was for an illegitimate purpose: to assist the president to delay his official response to the report of the public protector.

"We cannot say too strongly: those reports are totally without foundation."

Madonsela gave Zuma two weeks to respond to her report, but the president said he would only do so when he had also received that of the SIU.

He finally submitted a response to the various investigations into Nkandla to Parliament in mid-August, and in it made clear that he was neither commenting on, nor tacitly accepting, Madonsela's findings.

The president and the public protector have since been locked in a stand-off. Madonsela warned that his response was inadequate, while Zuma has said he did not consider himself obliged to "rubber stamp" her findings.

Opposition parties say the president's view runs counter to the Constitution.

Congress of the People leader Mosiuoa Lekota last week said his party refused to sit on the ad hoc committee because its mandate was to review the public protector's report, which by law only a court could do.

Maharaj declined to say when Zuma filed his response to the SIU.

"There is a parliamentary process now under way on Nkandla. We will adhere to that and not engage in responding to individual press reports," he said.

The unit found Zuma and his family were enriched by state-funded upgrades to his Nkandla home.

But, unlike Madonsela, it did not direct Zuma to reimburse the state for luxuries, such as a swimming pool, built at Nkandla. Instead, it is suing the president's architect, Minenhle Makhanya, for R155-million – its estimate of the state's total losses as a result of the project spiralling into what it terms "unacceptable extravagance".

Opposition parties are adamant that the task of the parliamentary committee is to ensure that the president follows Madonsela's directive to repay the state for perks added to Nkandla.

But the ruling party has in recent years taken a narrower interpretation of the powers given by law to the public protector and stressed that she accounts to Parliament.

On Monday, Zuma insisted in a written response to a parliamentary question from Lekota that he had "indeed relied on the constitutional and statutory provisions" regarding the public protector when he responded to her report, including the recommendation that he pay back a reasonable proportion of the money spent at Nkandla.

The committee meets again on Thursday.