Democratic Alliance (DA) leader John Steenhuisen has reiterated his party's call to establish an ad hoc committee on President Cyril Ramaphosa's Phala Phala scandal.

This after the Constitutional Court unanimously dismissed Ramaphosa's efforts to seek direct access to overturn an independent panel's findings he might have violated the Constitution and committed money laundering in connection with the ongoing Phala Phala saga.

The report had concluded there existed prima facie evidence that Ramaphosa might have committed a serious violation of the Constitution.

He had launched the court application to set aside the Section 89 report.

According to Steenhuisen, the judgment confirms the case could only be fully investigated, to the necessary extent, by a National Assembly ad hoc committee.

He said the DA would table a motion with National Assembly Speaker Nosiviwe Mapisa-Nqakula to establish an ad hoc committee on the Phala Phala matter.

The party wants to bring the case to the constitutional body empowered to deal with it.

"As we have previously argued, the Phala Phala scandal does not begin and end with the president, and as such, it necessitates an ad hoc committee that will have the full powers to summon and investigate Cabinet ministers, law enforcement bodies, and other state institutions allegedly involved in this cover-up," Steenhuisen said.

He added an ad hoc committee should have followed when the scandal first broke.

"The first witness that must be called by this committee, is Cyril Ramaphosa himself. It is highly irresponsible conduct by the president to bat the Phala Phala scandal between Parliament and the courts all in an attempt to evade difficult questions and full transparency and accountability."

Steenhuisen said Ramaphosa needed to take the country into his confidence about what truly transpired at Phala Phala in Parliament, "the body to which he is constitutionally obligated to account".

The apex court's ruling means the president will have to turn to the High Court if he wishes to challenge the report, which has been the basis of attacks on his leadership.

The court did not make findings on the merits of the Ramaphosa's case.